jQuery(document).ready(function() {

var randomnumber=Math.floor(Math.random()*3)

    if(randomnumber==0){
        jQuery('.backheader').css("background", "url(wp-content/themes/mcm/images/backHeader.jpg) no-repeat top center");
    }
    if(randomnumber==1){
        jQuery('.backheader').css("background", "url(wp-content/themes/mcm/images/backHeader2.jpg) no-repeat top center");
    }
    if(randomnumber==2){
        jQuery('.backheader').css("background", "url(wp-content/themes/mcm/images/backHeader3.jpg) no-repeat top center");
    }

});