function swap(string,i) {
	eval('document.button' + i + '.src = ' + string);
	}
	

//preload images

button1 = new Image();
button1.src = "images/guru_nav_r1_c1.gif";
button1over = new Image();
button1over.src = "images/guru_nav_r1_c1_over.gif";
button1sel = new Image();
button1sel.src = "images/guru_nav_r1_c1_sel.gif";
button1f4 = new Image();
button1f4.src = "images/guru_nav_r1_c1_f4.gif";

button2 = new Image();
button2.src = "images/guru_nav_r1_c2.gif";
button2over = new Image();
button2over.src = "images/guru_nav_r1_c2_over.gif";
button2sel = new Image();
button2sel.src = "images/guru_nav_r1_c2_sel.gif";
button2f4 = new Image();
button2f4.src = "images/guru_nav_r1_c2_f4.gif";

button3 = new Image();
button3.src = "images/guru_nav_r1_c3.gif";
button3over = new Image();
button3over.src = "images/guru_nav_r1_c3_over.gif";
button3sel = new Image();
button3sel.src = "images/guru_nav_r1_c3_sel.gif";
button3f4 = new Image();
button3f4.src = "images/guru_nav_r1_c3_f4.gif";

button4 = new Image();
button4.src = "images/guru_nav_r1_c4.gif";
button4over = new Image();
button4over.src = "images/guru_nav_r1_c4_over.gif";
button4sel = new Image();
button4sel.src = "images/guru_nav_r1_c4_sel.gif";
button4f4 = new Image();
button4f4.src = "images/guru_nav_r1_c4_f4.gif";

button5 = new Image();
button5.src = "images/guru_nav_r1_c5.gif";
button5over = new Image();
button5over.src = "images/guru_nav_r1_c5_over.gif";
button5sel = new Image();
button5sel.src = "images/guru_nav_r1_c5_sel.gif";
button5f4 = new Image();
button5f4.src = "images/guru_nav_r1_c5_f4.gif";

button6 = new Image();
button6.src = "images/back_green.gif";
button6over = new Image();
button6over.src = "images/back_green_over.gif";

button7 = new Image();
button7.src = "images/next_green.gif";
button7over = new Image();
button7over.src = "images/next_green_over.gif";