function boxchk(obj,max) {var box = obj.name.substr(0,obj.name.lastIndexOf('_')+1);var cnt=0,i=1;
while(obj.form[box+i]) {cnt += obj.form[box+i].checked;i++;}if (cnt > max) {obj.checked = false;
alert('Only choose ' + max + ' '+box.substr(0,box.length-1) +' checkboxes.\nTo pick this option unselect one of the others.');}}