Validate a form using javascript

We should validate a form for null values, otherwise user can click submit button without filling necessary information. In that case, our database will have many null values.

So below is a simple validation using javascript for validating a form.



First you need to create a form with neccessary values as below:

Html Code

  


    
Name
    

  

    
Email
    

  

    

    

  

Now, you when user will click submit button it will redirect to another page defined in action of form tag. But we want user to fill all the values of the form. So here we are using javascript function in "onsubmit" event as written above. Write your javascript inside header tag of your document.

Javascript Code

function validate(){

    

    var fullname=document.form1.fullname.value;

    var email = document.form1.email.value;

    

    var atpos = email.indexOf("@");

    var dotpos = email.lastIndexOf(".");

    if(fullname==""){

        alert("Enter Full Name");

        return false;

    }

     else if (atpos< 1 || dotpos<atpos+2 || dotpos+2>=x.length) {

        alert("Enter valid e-mail address");

        return false;

    }

    

    else {

        return true;

    }

}

</pre>

In above code, we are validating if the name field is empty or not. Also we are validating email field is empty or not along with if the user is giving valid email address.