function checkall(a,b){
	var obj=document.getElementsByName(a);
	var objall=document.getElementsByName(b);
  for (var i=0;i<obj.length;i++){
      obj[i].checked = objall[0].checked;
    }
}

function collect_checkbox_values(box){
    var val = "";
    var num=0;
    for (var i=0; i<box.length; i++){
        if ( box[i].value.length > 0 && box[i].checked == true) {
            val+= box[i].value+",";
            num++;
        }
    }
    val=val.replace(/,$/,'');
    return [val,num];
}