Javascript Validations | Numbers only validations

<html>
	<head>
    	<title>Javascript Numbers only validations</title>
    </head>
    <body>
	
		<style type="text/css">
			.lable{ 
				font-family:Arial, Helvetica, sans-serif; 
				font-size:13px; 
				font-style:italic; 
				margin:5px 0px; 
				font-weight:bold; 
				clear:both;
			}
			.cus_form{ 
				height:30px; 
				padding:0px 1px; 
				margin:2px 0px 10px;
			} 
			.cus_btn{
				padding:7px 15px; 
				border-radius:2px; 
				background:#09C; 
				color:#FFF; 
				margin-left:10px;
			}
			.cus_btn:hover{ background:#069;}
		</style>
			 
		<script type='text/javascript'>
			function isNumeric(elem, helperMsg){
			var numericExpression = /^[0-9]+$/;
			if(elem.value.match(numericExpression)){
			return true;
			}else{
			alert(helperMsg);
			elem.focus();
			return false;
			}
			}
		</script>

<form>
			<label class="lable">Numbers Only :</label>
			 <input type='text' id='numbers' class="cus_form" required />
			<input type='button' onclick="isNumeric(document.getElementById('numbers'), 'Please Enter Numbers Only')" class="cus_btn" value='Check Field' />
		</form>
        
    </body>
</html>

Output :

Topic : Numbers only validations