// Javascript for verifying that atmost single record is selected in the grid



function ChecksingleSelected(checkBox) {

var frm = document.forms[0];
var flag = false;
var cnt = 0;

for (var i = 0; i < document.forms[0].length; i++) {
if (document.forms[0].elements[i].id.indexOf(checkBox) != -1) {
if (document.forms[0].elements[i].checked) {
flag = true
cnt = cnt + 1;
}
}
}
if (cnt > 1) {

alert('Only record can be seleccte/checked.');
return false;
}

Read more: http://feeds.dzone.com/~r/dzone/snippets/~3/xXSwjmM3MZ8/14487