function next(){
 count++;
 if(count>imagesArray.length-1) count =0;
 document.getElementById("mainImg0").src = imagesArray[count];
 document.getElementById("mainImg0").alt = altArray[count];
 document.getElementById("imageText").innerHTML = altArray[count];
}
function prev(){
 count--;
 if(count<0) count=imagesArray.length-1;
 document.getElementById("mainImg0").src = imagesArray[count];
 document.getElementById("mainImg0").alt = altArray[count];
 document.getElementById("imageText").innerHTML = altArray[count];
}
//mac ie doesn't have a array.push function so we deinfe a new method of array here...
if(typeof Array.prototype.push=="undefined")
  Array.prototype.push=function(){
    var i=0;
    b=this.length,a=arguments;
    for(i;i<a.length;i++)this[b+i]=a[i];
    return this.length
  };