How to Show Hover Items Like Face Book

Hi,

In my project i developed same like face book application like, he can post their comments and like their comments and unlike their comments.

But i am unable to hover the posted liked names , same as face book.

<asp:TemplateColumn HeaderText="Like"><ItemTemplate><asp:Image id="imgLike" ToolTip=<%# DataBinder.Eval (Container.DataItem, "likes") %>                

                       runat="server"/></ItemTemplate></asp:TemplateColumn>

When i moved to the Like image it showing the Names of all peoples that post liked.

But i want the background color when we hover that image ,it shows all the liked names with background color.Same as like Face book.

There is no onmouseover function for this Image control.

So how can i do this one please help me.

Thanks.