function changbg1()
    {
    	document.getElementById('p1').style.background = "url('/style_new/image/midbga.jpg')";
    	document.getElementById('p2').style.background = "url('/style_new/image/midbg2.jpg')";
    	document.getElementById('p3').style.background = "url('/style_new/image/midbg3.jpg')";
    	document.getElementById('p4').style.background = "url('/style_new/image/midbg4.jpg')";
    }
    function changbg2()
    {
    	document.getElementById('p1').style.background = "url('/style_new/image/midbg.jpg')";
    	document.getElementById('p2').style.background = "url('/style_new/image/midbg2a.jpg')";
    	document.getElementById('p3').style.background = "url('/style_new/image/midbg3.jpg')";
    	document.getElementById('p4').style.background = "url('/style_new/image/midbg4.jpg')";
    }
    function changbg3()
    {
    	document.getElementById('p1').style.background = "url('/style_new/image/midbg.jpg')";
    	document.getElementById('p2').style.background = "url('/style_new/image/midbg2.jpg')";
    	document.getElementById('p3').style.background = "url('/style_new/image/midbg3a.jpg')";
    	document.getElementById('p4').style.background = "url('/style_new/image/midbg4.jpg')";
    }
    function changbg4()
    {
    	document.getElementById('p1').style.background = "url('/style_new/image/midbg.jpg')";
    	document.getElementById('p2').style.background = "url('/style_new/image/midbg2.jpg')";
    	document.getElementById('p3').style.background = "url('/style_new/image/midbg3.jpg')";
    	document.getElementById('p4').style.background = "url('/style_new/image/midbg4a.jpg')";
    }