Icon trigger not displaying

Icon trigger not displaying

I have the following code


   $( "#Date" ).datepicker({ numberOfMonths: 3,showButtonPanel: true, dateFormat: "yy-mm-dd", changeMonth:true, changeYear: true, showOn: "both", buttonimage:"calendar.gif", buttonImageOnly: true});  


However, the trigger ICON does not display. The GIF is in the same folder as the HTML page.