function MM_changeProp(objId,x,theProp,theValue) { //v9.0
  var obj = null; with (document){ if (getElementById)
  obj = getElementById(objId); }
  if (obj){
    if (theValue == true || theValue == false)
      eval("obj.style."+theProp+"="+theValue);
    else eval("obj.style."+theProp+"='"+theValue+"'");
  }
}


 function show_div(id1,id2,id3,id4,id5) 
	{
	
		MM_changeProp(id1,'','display','block','DIV');
		MM_changeProp(id2,'','display','none','DIV');
		MM_changeProp(id3,'','display','none','DIV');
		MM_changeProp(id4,'','display','none','DIV');
		MM_changeProp(id5,'','display','none','DIV');
      //}
	}
	
  function opt(f)
  {
  var selNum =f.cmbCores.selectedIndex;
  //document.write(selNum);
  var a= f.cmbCores.options[selNum].value;
  //document.write(selNum);
  //document.write(a);
 switch(selNum)
		 {
		 case 1:
		 //document.write(a);
		 show_div('id1','id2','id3','id4','id5')
		
		 break;
		 
		 case 2:
		 show_div('id2','id1','id3','id4','id5')
		
		  break;
		  
		   case 3:
		   show_div('id3','id1','id2','id4','id5')
	
		  break;
		  		  
		   case 4:
		   show_div('id4','id1','id2','id3','id5')
			break;
				  
		  case 5:
		  show_div('id5','id1','id2','id3','id4')
		  break;
		 }
    }