C# - Highlight Gridview Row In Update Panel Without Posting Back?

I have a gridview in an update panel with the following code to select a row, this in turn updates another updatepanel with details from the form record.

protected void gvMainGrid_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
//Make the entire row clickable to select this record
//Uses javascript to post page back
e.Row.Attributes["onmouseover"] = "this.style.cursor='hand';this.style.textDecoration='underline';";
e.Row.Attributes["onmouseout"] = "this.style.textDecoration='none';";
e.Row.Attributes.Add("onclick", ClientScript.GetPostBackClientHyperlink(this.gvMainGrid, "Select$" + e.Row.RowIndex));
}
}

I am manually binding the gridview from a database and don't want to rebind the grid just to highlight the row, but I can't seem to add any javascript to the onclick event, it seems to either show the GetPostBackClientHyperlink or the row highlight javascript.