Handle button click in gridview in combination with rowclick - asp.net

Question

I have a gridview in my asp.net application. We've added code to intercept row clicks anywhere on a row.
This works perfectly. Whenever a row is clicked, the RowCommandevent is fired.
(in this case it redirects the user to a different page)
Now I want to add a column with an Image which, when clicked, should not redirect the user, but fire some Javascript.
However, while the javascript is fired, the RowClick is also fired.
Is there a way to temporarily disable the RowClick?
Edit: Updated code
The gridview:
<asp:GridView id="OpleidingView" runat="server" SkinID="sknGridView" ShowHeader="false" AutoGenerateColumns="False" DataKeyNames="OPLEIDING_ID, OPLEIDING_OMSCHRIJVING, EIGENAAR">
<Columns>
<asp:Boundfield DataField="OPLEIDING_OMSCHRIJVING"></asp:BoundField>
<asp:Boundfield DataField="OPLEIDING_COLO_CODE"></asp:BoundField>
<asp:Boundfield DataField="OPLEIDING_COHORT"></asp:BoundField>
<asp:Boundfield DataField="OPLEIDING_CODE"></asp:BoundField>
<asp:Boundfield DataField="OPLEIDING_VERSIE"></asp:BoundField>
<asp:Boundfield DataField="OPLEIDING_LEERWEG"></asp:BoundField>
<asp:Boundfield DataField="OPLEIDING_NIVEAU"></asp:BoundField>
<asp:Boundfield DataField="OPLEIDING_VERWIJDERD"></asp:BoundField>
<asp:templatefield>
<ItemTemplate>
<asp:Image ID="imgDelen" runat="server"/>
</ItemTemplate>
</asp:templatefield>
</Columns>
</asp:GridView>
The Javascript function:
function Test()
{
alert("hi");
return false;
}
The RowDataBound event:
Protected Sub OpleidingView_RowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles OpleidingView.RowDataBound
If e.Row.RowType = DataControlRowType.DataRow Then
e.Row.Attributes("onclick") = ClientScript.GetPostBackEventReference(Me.OpleidingView, "Select$" & e.Row.RowIndex)
e.Row.ID = "Disable" & e.Row.RowIndex.ToString
Dim img As Image = CType(e.Row.FindControl("imgdelen"), Image)
img.ImageUrl = "~/Images/DefaultTheme/delen_zwart.png"
img.Attributes.Add("onclick", "return Test();")
End If
End Sub