Check if an input field is a number in Javascript
Sometimes the user needs to fill in one or more fields with numbers (0-9) in an HTML form. You can write a script in JavaScript to check if a field is a number.
Script to check if an input field is a number in Javascript
<html>
<head>
<script>
function check(){
var nbr=document.frm.nbr.value;
if (isNaN(nbr)){
document.getElementById("msg").innerHTML="Enter only a numeric value";
return false;
}else{
return true;
}
}
</script>
</head>
<body>
<form name="frm" onsubmit="return check()" >
Enter a number: <input type="text" name="nbr"><input type="submit" value="submit"><br>
<span id="msg" style="color:red"></span>
</form>
</body>
</html>
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