function fire_insurance() {
var sum;
var premium = "";
if (document.form1.sum_insured.value == "") {
alert("Please enter Sum Insured!");
document.form1.sum_insured.focus();
return;
}
sum = document.form1.sum_insured.value;
if(sum <= 5000000)
    premium = sum * 0.0005;
else if(sum > 5000000)
    premium = sum * 0.0004;
if(premium < 400)
    premium = 400;
    //premium = Math.round(premium);
    premium = Math.round(premium * 10) / 10 ;
    document.form1.fire_premium.value = premium;
}
function isNum(obj) {
var i, ch;
var str = obj.value;
if (str.substring(0,1) == "."){
alert("First digit should not be a single dot.")
return false;
}else{
for (i = 0; i < str.length; i++) {
ch = str.substring(i, i + 1)
if ((ch < "0" || "9" < ch) && ch != '.') {
alert(ch + " is not a number.")
obj.focus();
return false;
}
}
return true
}
}
function moneyFormat(input) { 
var dollars = Math.round(input);
var tmp = new String(input);
for (var decimalAt = 0; decimalAt < tmp.length; decimalAt++) {
if (tmp.charAt(decimalAt)==".") break;
}
var cents  = "" + Math.round(input * 100);
cents = cents.substring(cents.length-2, cents.length);
dollars += ((tmp.charAt(decimalAt+2)=="9")&&(cents=="00"))? 1 : 0;
return dollars + "." + cents;
}