function get_random_popup_name() { 
var random_name_part1 = Math.round(1000000 * Math.random()); 
random_name_part1 = random_name_part1.toString(); 
var random_name_part2 = Math.round(1000000 * Math.random()); 
random_name_part2 = random_name_part2.toString(); 
var random_name = random_name_part1 + '_' + random_name_part2; return random_name; 
} 

$(document).ready(function(){ 
var imagecount = 6; 
var rndNum = Math.floor(Math.random() * imagecount); 

$('body').css('background-image','url(img/bg_'+rndNum+'.jpg)'); 


}); // END JQUERY READY