var calDot = "";
var calValue = 0;
var IsCal = false;
var IsZero = true;
function insertNum(CalItem)
{
    var calField = document.getElementById("txtCal");
    if(IsZero == true)
    {
        calField.value = "0.";
        IsZero = false;
    }
    if(calField.value == "0.")
    {
        if(CalItem == ".")
        {
            calField.value = "0.";
            calDot = ".";
        }
        else
        {                    
            if(calDot == ".")
            {
                calField.value += CalItem;
            }
            else
            {
                calField.value = CalItem + ".";
            }
        }
    }
    else
    {            
        if(CalItem == ".")
        {
            calDot = ".";
        }
        else
        {                    
            if(calDot == ".")
            {
                calField.value += CalItem;  
            }
            else
            {
                var calVal = calField.value.substring(0,calField.value.length - 1);
                calField.value = calVal + CalItem + ".";  
            }
        }
    }
}
function clearAll()
{
    var calField = document.getElementById("txtCal");
    calField.value = "0."
    calDot = "";
    calValue = "";
    IsCal = false;
    IsZero = true;
}
function clearOne()
{
    var calField = document.getElementById("txtCal");
    var calVal = "0";            
    if(calDot != ".")
    {
        if(calField.value.length == 2)
        {
            calField.value = "0.";
        }
        else
        {
            calVal = calField.value.substring(0,calField.value.length - 2);
            calField.value = calVal + ".";
        }
    }            
    else
    {
        if(calField.value.substring(calField.value.length - 1,calField.value.length) == ".")
        {
            calDot = "";
        }
        else
        {
            calVal = calField.value.substring(0,calField.value.length - 1);
            calField.value = calVal;
        }
    }
}
function calculate(operator)
{
    var calField = document.getElementById("txtCal");
    IsZero = true;
    calDot = "";
    if(operator == "=")
    {
        if(calField.value.indexOf(".") == eval(calField.value.length - 1))
        {
            calField.value = eval(calValue + calField.value) + ".";                    
        }
        else
        {
            calField.value = eval(calValue + calField.value);                    
        }
    }
    else
    {
        if(IsCal == true)
        {
           IsCal = true;                   
           calField.value = eval(calValue + calField.value) + ".";
        }
        else
        {
            calValue = calField.value + operator;
        }
    }
}


/*----------------------------------------------------*/


function showpay() 
{
     if ((document.aspnetForm.txtLoanAmt.value == null || document.aspnetForm.txtLoanAmt.value.length == 0) ||
         (document.aspnetForm.txtLoanInMonth.value == null || document.aspnetForm.txtLoanInMonth.value.length == 0)
        || (document.aspnetForm.txtInterestRate.value == null || document.aspnetForm.txtInterestRate.value.length == 0))
     { 

        document.aspnetForm.txtMonthlyPay.value = "Incomplete data";
     }
     else
     {
        var lngLoanAmt = document.aspnetForm.txtLoanAmt.value;
        var lngTerm = document.aspnetForm.txtLoanInMonth.value;
        var lngInterest = (document.aspnetForm.txtInterestRate.value) / 100;
        document.aspnetForm.txtMonthlyPay.value = lngLoanAmt * lngInterest / (1 - (Math.pow(1/(1 + lngInterest), lngTerm)));
     }
}
function percentcal1()
{
    lngA = (document.aspnetForm.txtA.value) / 100;
    lngB = lngA * (document.aspnetForm.txtB.value);
    document.aspnetForm.txtAnswer1.value = lngB;
}
function percentcal2()
{
    lngC = (document.aspnetForm.txtC.value) / (document.aspnetForm.txtD.value);
    lngD = lngC * 100;    
    document.aspnetForm.txtAnswer2.value = lngD;
}