function checkAll() {
var Ckall= document.getElementById("cAll");
var Cks = document.getElementsByName("c");
for(var i=0;i<Cks.length;i++)
{
Cks[i].checked=Ckall.checked;
}
}
Window.onload=function(){
Var ck= Document.getelementbyid(“cAll”);
Ck.onclick=checkAll;
}