function UpdateBalance() {
balance.value = totalincome.value - totalexp.value
}
function CalculateMortgage() {
if (document.loanform.interest.value == 0)
	{
	document.loanform.principal.value = "";
	return false;
	}
var monthlyinterest = document.loanform.interest.value * 0.01 / 12.0;
var x = Math.pow((1 + (monthlyinterest)), (document.loanform.term.value * 12));
var balance = (document.loanform.totalincome.value - document.loanform.totalexp.value) * 0.8;
document.loanform.principal.value = Math.round((balance * (x - 1))/((monthlyinterest) * x));
return false;
}
function clearfields() {
document.loanform.totalincome.value = ""
document.loanform.totalexp.value = ""
document.loanform.term.value = ""
document.loanform.interest.value = 6.5
document.loanform.principal.value = ""
return false
}
function makenum(newNumber){
newStr=new String
strLength=newNumber.length
i=0
while (i<=strLength){
tmpChar=newNumber.charAt(i)
if (tmpChar=="-" || tmpChar=="+" || tmpChar==")" || tmpChar=="+" || tmpChar==")" || tmpChar=="(" || tmpChar=="*" || tmpChar=="&" || tmpChar=="#" || tmpChar=="!" || tmpChar=='"' || tmpChar=="/" || tmpChar=="'" || tmpChar=="$" || tmpChar==";" || tmpChar==" " || tmpChar=="%"){tmpChar="h"}


testChar=parseInt(tmpChar)
if((tmpChar=="." || tmpChar<="9") && tmpChar != ",") {newStr=newStr+tmpChar}
i++
}
return newStr
}
function clearall(){
                document.loanform.amt.value=""
                document.loanform.pmt.value=""
                document.loanform.term.value=""
                document.loanform.rate.value=""
                document.loanform.result.value=""
				return false
}


function dopmt(){
        var amt=0
        var rate=0
        var term=0
        amt=amt + makenum(document.loanform.amt.value)
        rate=rate + document.loanform.rate.value
        term=term + document.loanform.term.value
<!--------------check to see if required fields contain info---------------->
        if (amt<=0){document.loanform.result.value="Please enter the desired Loan amount"}
        else if (rate<=0){document.loanform.result.value="Please enter the desired Interest rate"}
        else if (term<=0){document.loanform.result.value="Please enter the desired Term amount"}
        else {
                        if(term<1){term = 1}
                        if(rate<1){rate = 1}
                        if(amt<1){amt = 0}
                rate = (rate / 100) <!-- make percentage -->
                        var pmt = 0
                        x = (rate/12)
                        y = 1+(rate/12)
                        z = -(term*12)
                pmt =((x/(1-(Math.pow(y,z))))*amt)
<!-----------Round to nearest decimal and return pmt as 2 decimal number---------->
                        pmt=pmt*100
                        pmt=Math.round(pmt)
                        pmt=pmt/100
        document.loanform.result.value="Approximate monthly payment = $"+pmt
        document.loanform.pmt.value=pmt
}
return false;
}


function dorate(){
var amt=0
var pmt=0
var term=0
amt=amt + makenum(document.loanform.amt.value)
pmt=pmt + makenum(document.loanform.pmt.value)
term=term + document.loanform.term.value
<!--------------check to see if required fields contain info---------------->
                if (amt<=0){document.loanform.result.value="Please enter the desired Loan amount"}
        else if (pmt<=0){document.loanform.result.value="Please enter the desired Payment amount"}
        else if (term<=0){document.loanform.result.value="Please enter the desired Term amount"}
        else {
                        var x=9
                        var y=100
                        var n=term*12
                        var rate=0
        while (x<=y){

                        y=x
                if (rate>=101){;break}
                        rate=rate+.01
                        var mrate=rate/(100*12)
                        var r=1+mrate
                        var d=r-1
                        var e=Math.pow(r,-n)
                        var a=Math.round(pmt*(1-e)/d)
                        x=Math.abs((a-amt)/amt)
document.loanform.result.value="solving for rate! "+ rate
}                                       if (rate<=1){document.loanform.result.value="No solution. Please adjust values!"}
                        else if(rate>=101){document.loanform.result.value="No solution. Please adjust values!"}
                        else{rate=rate-.01
<!--------------round rate to 2 decimal places----------------->
                        rate=rate*100
                        rate=Math.round(rate)
                        rate=rate/100
                                document.loanform.result.value="Approximate interest rate = "+rate +"%"
                                document.loanform.rate.value=rate
}}
return false;
}


function doamt(){
var rate=0
var pmt=0
var term=0
term=term + document.loanform.term.value
pmt=pmt + makenum(document.loanform.pmt.value)
rate=rate + document.loanform.rate.value
<!--------------check to see if required fields contain info---------------->
                if (rate<=0){document.loanform.result.value="Please enter the desired Interest rate"}
        else if (pmt<=0){document.loanform.result.value="Please enter the desired payment amount"}
        else if (term<=0){document.loanform.result.value="Please enter the desired Term amount"}
        else {
                        if(term<1){ term = 0}
                        if(rate<1){rate = 1}
                        if(pmt<1){pmt = 1}
                        rate = (rate / 100) <!-- make percentage -->
                        var amt = 0
                        x = (rate/12)
                        y = 1+(rate/12)
                        z = -(term*12)
                        amt =Math.round(pmt/(x/(1-(Math.pow(y,z)))))
                                document.loanform.result.value="Approximate Loan Amount = $"+amt
                                document.loanform.amt.value=amt
}
return false;
}


function doterm(){
var amt=0
var pmt=0
var rate=0
amt=amt + makenum(document.loanform.amt.value)
pmt=pmt + makenum(document.loanform.pmt.value)
rate=rate + document.loanform.rate.value
<!--------------check to see if required feilds contain info---------------->
                if (amt<=0){document.loanform.result.value="Please enter the desired Loan amount"}
        else if (rate<=0){document.loanform.result.value="Please enter the desired Interest rate"}
        else if (pmt<=0){document.loanform.result.value="Please enter the desired payment amount"}
                else {
                                if(amt<1){ amt = 0}
                        if(rate<1){rate = 1}
                        if(pmt<1){pmt = 1}
                        rate = (rate / 100) <!-- make percentage -->
                        var term = 0
                        i = (rate/12)
                        n=term*12
                        r=1+i
                        g=(r-1)*amt
                        h=g/pmt
                        j=1-h
                        k=1/j
                        term =Math.round(Math.log(k)/Math.log(r))
                        yr=Math.round(10*(term/12))/10
                if (term>01){document.loanform.result.value="Loan Period is "+ term +" months or " + yr +" years.",document.loanform.term.value=yr}
                        else {document.loanform.result.value="No solution Please adjust your values"}
}
return false;
}