Using onkeyup event of the textbox we can show the message " enter age between 1 to 100 " when entering age more than 100.
Following code for this event
HTML
<label>Enter Your Age : </label>
<input type="text" id="txtAge" onkeyup="ageValidation()">
Javascript
function ageValidation()
{
var x = document.getElementById("txtAge").value;
if (x < 1 || x > 100)
{
alert("enter age between 1 to 100")
}
}