var loading_graphic = new Image();
loading_graphic.src = '/images/loading.gif';

function displayLoadingGraphic( button ) {
	
	var loading_block = document.createElement('div');
	loading_block.className = 'loading';
	loading_block.appendChild( loading_graphic );
	button.parentNode.appendChild( loading_block );
	button.style.display = 'none';
	button.style.visibility = 'hidden';
}

function sleep(milliseconds) {
  var start = new Date().getTime();
  for (var i = 0; i < 1e7; i++) {
    if ((new Date().getTime() - start) > milliseconds){
      break;
    }
  }
}