Change events

by isogunro

HTML

<input type="text" id="fName" placeholder="Enter First Name" />
<div id="ruleViolation"></div>

JavaScript

document.getElementById("fName").focus();
document.getElementById("fName").addEventListener("blur", function(){
    if(this.value.length<5) {
        document.getElementById("ruleViolation").innerText = 'First Name is Required.';
        document.getElementById("ruleViolation").style.color = 'red';
        this.focus();
    }
    
});