when image click want to navigate another page

Hi

<img src='" + targetTable.Rows[i]["ProductImage"] + "'   onclick='ImgClick(this.id)' id='" + targetTable.Rows[i]["id"] + "' title='Sample Baby Hat' width='190px'/></a>

when i image click javascript il be called but doesnot go my Product.aspx page..

Javascript

function ImgClick(obj) {

window.location.assign("Product.aspx?Value=" + obj + "");--here called function but doesnot go product.aspx page
}

Thanks