JScript Querystringer

Introduction

One of the things that can get overlooked in web development is the fact that you can pass parameters to HTML pages without having to bounce a redirect statement off the server. This can be pretty useful if the HTML page is a generic that loads various xml files based on that parameter (like a product details page with a productID being passed). Here's the code:

function retVal(sName)
{

  /*
   get last loc. of ?
   right: find first loc. of sName
   +2
   retrieve value before next &
  
  */
  
  var sURL = new String(window.location);
  var iQMark= sURL.lastIndexOf('?');
  var iLensName=sName.length;
  
  //retrieve loc. of sName
  var iStart = sURL.indexOf('?' + sName +'=') //limitation 1
  if (iStart==-1)
        {//not found at start
        iStart = sURL.indexOf('&' + sName +'=')//limitation 1
		if (iStart==-1)
		   {//not found at end
		    return 0; //not found
		   }   
        }
        
  iStart = iStart + + iLensName + 2;
  var iTemp= sURL.indexOf('&',iStart); //next pair start
  if (iTemp ==-1)
		{//EOF
		iTemp=sURL.length;
		}  
  return sURL.slice(iStart,iTemp ) ;
  sURL=null;//destroy String
}


alert( retVal('mynewname'));

Usage:

Save the code into a normal HTML page and call it like this:

mypage.htm?mynewname=testvalue

and "testvalue" should be returned in the alert box. The "mynewname" is just a literal and can be replaced with any querystring name that has a value related to it.