Loading Image

Loading Image is used during processing of record. 

Add following css
#loading-image {
 position: fixed;
 top: 40%;
 left: 50%;
}
#loading {
 width: 100%;
 height: 100%;
 top: 0px;
 left: 0px;
 position: absolute;
 display: none;
 opacity: 0.5;
 filter: alpha(opacity = 50);
 -moz-opacity: 0.5;
 background-color: #fff;
 text-align: center;
 z-index: 100;
}

Add following javascript code
//function for showing loading image
function showLoadingImage() {
 document.getElementById('loading').style.display='block';
}


//function for hiding loading image
function hideLoadingImage() {
 document.getElementById('loading').style.display='none';
}

Add loading image in static resource with name LoadingImg and following html code