js一个简单的全选功能

function selectAll(){
            var checklist = document.getElementsByName ("selected");
            if(document.getElementById_x("controlAll").checked)
            {
                for(var i=0;i
                {
                    checklist[i].checked = 1;
                }
            }else{
                for(var j=0;j
                {
                    checklist[j].checked = 0;
                }
            }
        }   

input type="checkbox" name="selected" value="1"
input type="checkbox" name="selected" value="2"
input type="checkbox" name="selected" value="3"
input type="checkbox" name="selected" value="4"
input type="checkbox" name="selected" value="5"