function changeshirt() {
var shirt=new Array(5);
shirt[0] = 'assets/images/pricet-images/shirtcolors/blue.png';
shirt[1] = 'assets/images/pricet-images/shirtcolors/green.png';
shirt[2] = 'assets/images/pricet-images/shirtcolors/red.png';
shirt[3] = 'assets/images/pricet-images/shirtcolors/purple.png';
shirt[4] = 'assets/images/pricet-images/shirtcolors/white.png';
var whichShirt = Math.round(Math.random()*4);
document.getElementById('cool_picture').style.backgroundImage = "url(" + shirt[whichShirt] + ")";
//alert ("script is running" + " " + whichShirt + " " + shirt[whichShirt]);
}