$(document).ready( function(){ 
	 $("#header img").mouseenter(
		 function()
		 {
		 this.src = this.src.replace("_i","_o");
		 }
	);
	 $("#header img").mouseleave(
 		 function()
		 {
		 this.src = this.src.replace("_o","_i");
		 }
	); 
	 	
	} )