onServerClick when clicking on an html span element

I have a tag and I would be interested to click on it to run an event on the server (onServerClick)

I have the following:

<span style ="text-decoration:underline; cursor: pointer;" id="link1" runat="server" onServerClick="linkModificar_Click">Modificar</span>

But it does not jump to the event method on the server. On the other hand if I put an element if it does.

On the server side to pick up the event I've declared it like this:

protected void linkModificar_Click(object sender, EventArgs e)
{
  // Codigo 
}