.NET 3.5 GridView - Select multiple rows with Control key press

var isCtrl = false;

$('.GridViewRow').keyup(function (e) {<br/>
if(e.which == 17) isCtrl=false;<br/>
}).keydown(function (e) {<br/>
if(e.which == 17) isCtrl=true;<br/>
}<br/>
});<br/>

$('.GridViewRow').onclick(function (e) {
      // your row on click code goes here
});

<script language="JavaScript" src="JQuery.js"></script>