//用于在DataGrid实现全选---------------------------------------------------
function All() 
{
 var whichIt = event.srcElement;
 while (whichIt.tagName.indexOf("FORM") == -1) 
 { whichIt = whichIt.parentElement;
  if (whichIt == null) { return true; }
 }
 
 var length = whichIt.elements.length 
  var tocheck = true; 
 if(whichIt.btnSelAll.value=="全选"){
	whichIt.btnSelAll.value="全不选";
	tocheck=true;
 }
 else{
	whichIt.btnSelAll.value="全选";
	tocheck=false;
 }

 for (var i=0; i<length; i++) 
 { 
  if (whichIt.elements[i].name.indexOf("d") != -1) 
  whichIt.elements[i].checked = tocheck 
 } 
 return; 
}