Forms Data Controls :: Div Can't Show When Click On It?

I have below code structure and don't know why div cannot show when click on it???

<asp:GridView ID="gvwOrderLine"...
<asp:TemplateField>
<ItemTemplate>
<a href="javascript:expandcollapse('div<%# Eval("OrderLineID") %>');"> >></a> // cannot show??
<a href="javascript:expandcollapse('div<%# Eval("OrderLineID") %>AltBom');"> >></a> // cannot show??
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<tr>
<td colspan="100%" align="center">
<div id="div<%# Eval("OrderLineID") %>"...........
</div>
</td>
</tr>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField>
<ItemTemplate>
<tr>
<td colspan="100%" align="center">
<div id="div<%# Eval("OrderLineID") %>AltBom" ..............