n=4;// number of all gifs 
g=1;//number of random gifs 

//no need to modify bellow 
var theImages = new Array() //array of gifs 
for(var i=0;i<n;i++){ 
theImages[i]='images/face'+i+'.jpg'; 
} 
//randomize function 
function rand(){  
r = Math.floor(Math.random()*n);  
return r; 
}  
function showImages(){ 
var rr = new Array()//array of radom numbers 
rr[0]=-1; 
for(var j=0;j<g;j++){ 
rand(); 
for(var k=0;k<rr.length;k++){//check whether new random number reapets a former one or not 
    if(k!=j&&r==rr[k]){ 
    var j=j-1;break
    } 
	else{rr[j]=r;}//if not, create new array's element
} 
document.getElementById('face2').setAttribute('src',theImages[rr[j]]);//set new image 
} 
}