LinkButton with image and Text, Complete should be clickable

Hello Evrybdy,
In my design i have one big button with small image over it and text at the bottom on it, so i have done this with below code 
 <asp:LinkButton ID="BtnAllCustomer" runat="server" style="cursor:pointer;display:block;" CssClass="big-button" onclick="BtnAllCustomer_Click" >
               <p style="margin:0px; margin-bottom:15px; margin-top:5px; height:55px; overflow:hidden"><img src="../images/all-customer-icon.png" /></p>
               <span>
               ALL CUSTOMERS</span>
            </asp:LinkButton>
I have used linkButton, but it will not clickable on image over it, i want ...