var expd = 30;
var exp = new Date();
exp.setTime(exp.getTime() + (expd*24*60*60*1000));

function GetCookie (name) {
 var arg = name + "=";
 var alen = arg.length;
 var clen = document.cookie.length;
 var i = 0;
 while (i < clen) {
  var j = i + alen;
  if (document.cookie.substring(i, j) == arg)
  return getCookieVal (j);
  i = document.cookie.indexOf(" ", i) + 1;
  if (i == 0) break;
 }
 return null;
}
function getCookieVal (offset) {
 var endstr = document.cookie.indexOf (";", offset);  
 if (endstr == -1)    
 endstr = document.cookie.length;  
 return unescape(document.cookie.substring(offset, endstr));
}
function DeleteCookie (name) {
 var today = new Date();
 var expired = new Date(today.getTime() - 48 * 60 * 60 * 1000); // less 2 days
 document.cookie = name + "=null; expires=" + expired.toGMTString();
}
function SetCookie (name, value) {  
 var argv = SetCookie.arguments;  
 var argc = SetCookie.arguments.length;  
 var expires = (argc > 2) ? argv[2] : null;  
 var path = (argc > 3) ? argv[3] : null;  
 var domain = (argc > 4) ? argv[4] : null;  
 var secure = (argc > 5) ? argv[5] : false;  
 document.cookie = name + "=" + escape (value) + 
  ((expires == null) ? "" : ("; expires=" + expires.toGMTString())) + 
  ((path == null) ? "" : ("; path=" + path)) +  
  ((domain == null) ? "" : ("; domain=" + domain)) +    
  ((secure == true) ? "; secure" : "");
}
function round2(x) {
 x = Math.round(x * 100) / 100;
 x = (x + 0.001) + '';
 x = x.substring(0, x.indexOf('.') + 3);
 return x;
}
function round4(x) {
 x = Math.round(x * 10000) / 10000;
 x = (x + 0.00001) + '';
 x = x.substring(0, x.indexOf('.') + 5);
 return x;
}