function DisplayAlert(id,left,top) {
document.getElementById(id).style.left=left+'px';
document.getElementById(id).style.top=top+'px';
document.getElementById(id).style.display='block';
}

function DoSomething() {
var something = false;
if(something) {
   // do this section
   }
else {
   DisplayAlert('AlertBox',700,250);
   }
}