function checkWidth(){
  
 
  // to define a body-class
  if (self.innerHeight) // all except ie
 {
   x = self.innerWidth-20;
 }
 else if (document.documentElement && document.documentElement.clientHeight)
   // ie6 Strict Mode
 {
   x = document.documentElement.clientWidth;   
 }
 else if (document.body) // other ie
 {
   x = document.body.clientWidth;
 }
 //alert(x);
 if (x>=1024){
   className='wBig';
 } else if(x>=800){
   className='w1024';
 }else{
   className='w800';
 }
 document.body.className=document.body.className+' '+className;
}