function formatCurrency(num) {
	num = num.toString().replace(/\$|\,/g,'');
	if(isNaN(num))
	num = "0";
	sign = (num == (num = Math.abs(num)));
	num = Math.floor(num*100+0.50000000001);
	cents = num%100;
	num = Math.floor(num/100).toString();
	if(cents<10)
	cents = "0" + cents;
	for (var i = 0; i < Math.floor((num.length-(1+i))/3); i++)
	num = num.substring(0,num.length-(4*i+3))+','+
	num.substring(num.length-(4*i+3));
	return (((sign)?'':'-') + '$' + num + '.' + cents);
}

function getValue(num)
{
    var noJunk = ""
    var withDollar = ""
    var foundDecimal = 0
    var foundAlphaChar = 0
    num += "";

    if (num == "") { return(0); }
    for (i=0; i <= num.length; i++)
    {
        var thisChar = num.substring(i, i+1);
        if (thisChar == ".")
        {
          foundDecimal = 1;
          noJunk = noJunk + thisChar;
        }
        if ((thisChar < "0") || (thisChar > "9"))
        {
          if ((thisChar != "$") && (thisChar !=".") && (thisChar != ",") && (thisChar != " ") && (thisChar !="")) foundAlphaChar = 1;
        }
        else
 {
    withDollar = withDollar + thisChar
    noJunk = noJunk + thisChar
 }

 if ((thisChar == "$") || (thisChar == ".") || (thisChar == ","))
 {
   withDollar = withDollar + thisChar
 }
  }
     if (foundDecimal) { return parseFloat(noJunk); }
     else if (noJunk.length > 0) { return parseFloat(noJunk); }
     else return 0;
}

function downTime()
{   
    //init all variables
	var g5  = getValue(document.downtime.g5.value);
	var g6  = getValue(document.downtime.g6.value);
	var g61  = getValue(document.downtime.g6.value);
	var g7  = getValue(document.downtime.g7.value);
	var g8  = getValue(document.downtime.g8.value);
	var g9  = getValue(document.downtime.g9.value);
	var g10 = getValue(document.downtime.g10.value);
	var g11 = getValue(document.downtime.g11.value);
	var g12 = getValue(document.downtime.g12.value);
	var g13 = getValue(document.downtime.g13.value);
	var g14 = getValue(document.downtime.g14.value);
	var g15 = getValue(document.downtime.g15.value);
	
	//guts of the math
	g7  = g5 / 12;
	g8  = g7 * 0.25;
	g9  = g7 + g8;
	g10 = g9 / (30 * 4.333333);
	g11 = (g6 / 52) / 30;
	g12 = g10 + g11;
	g14 = (g12 * g13);
	g16 = g14 * g15;
	g18 = g16 * 12;
	
	//return results
	document.downtime.g7.value  = formatCurrency(g7);
	document.downtime.g8.value  = formatCurrency(g8);
	document.downtime.g9.value  = formatCurrency(g9);
	document.downtime.g10.value = formatCurrency(g10);
	document.downtime.g11.value = formatCurrency(g11);
	document.downtime.g12.value = formatCurrency(g12);
	document.downtime.g14.value = formatCurrency(g14);
	document.downtime.g16.value = formatCurrency(g16);
	document.downtime.g18.value = formatCurrency(g18);
	
    return true;
};