Javascript Email Validation

Email Validation

JavaScript for Email Address Validation

In forms when using email ID fields it is a good idea to use client side validation along with your programming language validation. The following example shows how you can validate an email address for a form. This javascript validation code is cross browser compatible (works for all browsers).

Email Validation Example

Example of email validation

View Explanation of the Code

Cut and Paste Code

Cut 'n' paste code for the above Example

JavaScript Code

/**

* DHTML email validation script. Courtesy of SmartWebby.com (http://www.smartwebby.com/dhtml/)

function echeck(str) {

var at="@"

var dot="."

var lat=str.indexOf(at)

var lstr=str.length

var ldot=str.indexOf(dot)

if (str.indexOf(at)==-1){

alert("Invalid E-mail ID")

return false

}

if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){

alert("Invalid E-mail ID")

return false

}

if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){

alert("Invalid E-mail ID")

return false

}

if (str.indexOf(at,(lat+1))!=-1){

alert("Invalid E-mail ID")

return false

}

if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){

alert("Invalid E-mail ID")

return false

}

if (str.indexOf(dot,(lat+2))==-1){

alert("Invalid E-mail ID")

return false

}

if (str.indexOf(" ")!=-1){

alert("Invalid E-mail ID")

return false

}

return true

}

function ValidateForm(){

var emailID=document.frmSample.txtEmail

if ((emailID.value==null)||(emailID.value=="")){

alert("Please Enter your Email ID")

emailID.focus()

return false

}

if (echeck(emailID.value)==false){

emailID.value=""

emailID.focus()

return false

}

return true

}

</script>

HTML Code

Explanation of the Code

The JavaScript has two functions:

Function echeck is used to verify if the given value is a possible valid email address. This function simply verifies the following:

It makes sure the email address has only one (@) and that it is not at the end or beginning of the email address.
It makes sure the email address has atleast one (.) after the @.
atleast one (.). It also makes sure that there are no spaces, extra '@'s or a (.) just before or after the @. It also makes sure that there

Function ValidateForm is used to make sure that the email field is not blank and that it is a valid email address on form submission.

Javascript Email Validation

Cross browser Email Validation in JS

Email Validation

JavaScript for Email Address Validation

Email Validation Example

Example of email validation

Cut and Paste Code

Cut 'n' paste code for the above Example

Explanation of the Code

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