Gridview image Hover

function zoom(img){
img.style.width = img.offsetWidth + 50 + "px";
}

function zoomOut(img){
 img.style.width = img.offsetWidth - 50 + "px";
}

you need to attach these functions on every image inside grid on two events onmouseover and onmouseout. You can use GridView1 RowDataBound event for this.Below is sample.

<img src=badge1blue.gif style="height"  onmouseover="zoom(this)" onmouseout="zoomOut(this)"/>