if(document.images){ // preload images
        pic7 = new Image(141,44); pic7.src = "buttons/home_out.gif";
        pic7_on = new Image(141,44);  pic7_on.src = "buttons/home_over.gif";
        pic1 = new Image(141,44); pic1.src = "buttons/kete_out.gif";
        pic1_on = new Image(141,44);  pic1_on.src = "buttons/kete_over.gif";
        pic2 = new Image(141,44); pic2.src = "buttons/educ_out.gif";
        pic2_on = new Image(141,44);  pic2_on.src = "buttons/educ_over.gif";
        pic3 = new Image(141,44); pic3.src = "buttons/t2001_out.gif";
        pic3_on = new Image(141,44);  pic3_on.src = "buttons/t2001_over.gif";
        pic4 = new Image(141,44); pic4.src = "buttons/t2000_out.gif";
        pic4_on = new Image(141,44);  pic4_on.src = "buttons/t2000_over.gif";
        pic5 = new Image(141,44); pic5.src = "buttons/amanas_out.gif";
        pic5_on = new Image(141,44);  pic5_on.src = "buttons/amanas_over.gif";
        pic6 = new Image(141,44); pic6.src = "buttons/multimedia_out.gif";
        pic6_on = new Image(141,44);  pic6_on.src = "buttons/multimedia_over.gif";
    }

function swap(imageName,imageFile){
        if(!document.images) return;
        eval('document.images[imageName].src='+imageFile+'.src');}