function disableselect(e)
{
  return false;
}

function reEnable()
{
  return true;
}

if (typeof document.onselectstart!="undefined")
{ 
 //IE : object
 document.onselectstart=new Function ("return false"); 
}
else
{
 // Mozilla
 document.onmousedown=disableselect;
 document.onmouseup=reEnable;
}