Hi,
Give the button a class name in properties (lets call it here as "X"), then create new CSS file and write in it:
.X:hover:after{
background: #FFFFFF;
border:1px solid;
border-color:#666666;
border-radius: 5px;
top: 60px;
color: #333333;
content: "Click here to print";
left: 50%;
padding: 5px 15px;
position: absolute;
z-index: 88;
width: 150px;
box-shadow: 1px 1px 3px #888888;
}
Most of the things I wrote is for design, the most important thing is the content.
Link your application with the CSS file you wrote, and you are done...