//*** This code is copyright 2002-2003 by Gavin Kistner and Refinery; www.refinery.com
//*** It is covered under the license viewable at http://phrogz.net/JS/_ReuseLicense.txt
//*** Reuse or modification is free provided you abide by the terms of that license.
//*** (Including the first two lines above in your source code satisfies the conditions.)

//***Adds a new class to an object, preserving existing classes
function AddClass(obj,cName){ 
   KillClass(obj,cName);
   return obj && (obj.className += (obj.className.length>0?' ':'')+cName);
}

//***Removes a particular class from an object, preserving other existing classes.
function KillClass(obj,cName){ 
   return obj && (obj.className=obj.className.replace(new RegExp("^" + cName + "\\b\\s*|\\s*\\b" + cName + "\\b",'g'),''));
}

//***Returns true if the object has the class assigned, false otherwise.
function HasClass(obj,cName){ 
   return (!obj || !obj.className) ? false:(new RegExp("\\b" + cName + "\\b")).test(obj.className); 
}