Add Onclick Or Mouseover Event To Imagebutton At Runtime?

ive imagebuttons which created in runtime from database and i need to add them onclick or mouseover event but i failed imagebutton.click += new ImageClickEventHandler(imageButton_Click); im adding this when i created imagebuttons, what i need else also i tried javascript but its not firing too;

<script type="text/javascript">
function SetProductImage(imgID) {
document.getElementById('imgProduct').src=document.getElementById(imgID).src;
}
</script>
imgProductImage.Attributes["onclick"] = "javascript:SetProductImage('" + imgProductImage.ID + "')";