CODEWITHSUNDEEP
javascriptvalidation
user1836389
user1836389

Reputation:

javascript empty field form validation not working

Hi I am new to javascript.

I am trying to implement some javascript form validation I am trying to use the technique used here: http://www.w3schools.com/js/tryit.asp?filename=tryjs_form_validation to test for empty field in the form and using an alert to warn users But it is not work for me When i submit an empty form proceeds to the jsp file and the javascript does not catch the error

here is my index.html file where the form is

<html>
  <body>
    <head>
    <script>
        function validateForm()
        {
            var stoneField=document.forms["bmiForm"]["stone"].value;
            var poundsField=document.forms["bmiForm"]["pounds"].value;
            var kgsField=document.forms["bmiForm"]["kgs"].value;
            var feetField=document.forms["bmiForm"]["feet"].value;
            var inchesField=document.forms["bmiForm"]["inches"].value;

            if ( stoneField = null || stoneField = "" && poundsField = null || poundsField = "" && kgsField = null || kgsField = "" && feetField = null || feetField = "" && inchesField = null || inchesField = "" )
            {
              alert("Please enter a weight and height");
              return false;
            }
            else
            {

             return true;
            } 
        }
    </script>
</head>
<form name ="bmiForm" action="PrintBMI.jsp" onsubmit="return validateForm()" method=post  style="width:250px;">
    <fieldset>
    <legend>BMI Calculator</legend>
    <h3>Enter your weight</h3>
    Stone <input type = text name = "stone" size = 1 maxlength = 2>
    Pounds <input type = text name = "pounds" size = 1 maxlength = 2>
    <br>
    <strong>OR</strong>
    <br>
    KGs <input type = text name = "kgs" size = 1 maxlength = 3>

    <h3>Enter your height</h3>
    Feet <input type = text name = "feet" size = 1 maxlength = 1>
    Inches <input type = text name = "inches" size = 1 maxlength = 2>
    <br>
    <strong>OR</strong>
    <br>
    Metres <input type = text name = "metres" size = 1 maxlength = 4>
    <p><input type=submit value = "Get BMI">
    </fieldset>
</form>
</body>
</html>'

Does anyone see what I'm doing wrong. Thanks for your time.

Upvotes: 1

Views: 1708

Answers (3)

Kingk
Kingk

Reputation: 1023

USE == for comparing value.

replace below block of code in your code.

if ( stoneField == null || stoneField == "" && poundsField == null || poundsField == "" && kgsField == null || kgsField == "" && feetField == null || feetField == "" && inchesField == null || inchesField == "" )

Upvotes: 0

Eduard
Eduard

Reputation: 3671

if ( stoneField = null || stoneField = "" && poundsField = null || poundsField = "" && kgsField = null || kgsField = "" && feetField = null || feetField = "" && inchesField = null || inchesField = "" )
        {
          alert("Please enter a weight and height");
          return false;
        }

Use === inside if, not =

Upvotes: 0

dfsq
dfsq

Reputation: 193251

Replace = to === in this code:

if ( stoneField = null || stoneField = "" && poundsField = null || poundsField = "" && kgsField = null || kgsField = "" && feetField = null || feetField = "" && inchesField = null || inchesField = "" )

Read about Comparison Operators

Upvotes: 1

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