I trying to create this form that only allows people to submit an email that is using a @msu.edu email. I have the alert that is coming up when it's not a msu.edu email, but when I use an email like [email protected] its not submitting the form.
function checkMail() { var email = document.validation.email.value.toLowerCase(); var filter = /^([\w-]+(?:\.[\w-]+)*)@msu.edu/i; var result = filter.test(email); alert('Valid email found: ' + result); return result; } You need to escape the . there.
Correct code:
function checkMail() { var email = document.validation.email.value.toLowerCase(); var filter = /^([\w-]+(?:\.[\w-]+)*)@msu\.edu/i; // ^-- escape this dot var result = filter.test(email); alert('Valid email found: ' + result); return result; } 
@msukedu, @msupedu, etc. as valid — which we assume isn't.
if like if (result === true) postPHPrequest(); else alert("Invalid email entered");Format in just like this... var filter = /^([\w-]+(?:\.[\w-]+)*)@msu\.edu/i; as per Gaurang said. It works.
why not try this
bool IsValidEmail(string email) { try { var addr = new System.Net.Mail.MailAddress(email); return true; } catch { return false; } } 
This will do it
put this function onclick event of button and change getelementById's Id with your TextBox Id and this will give you alert "msu.edu"
function checkMail() { var email = document.getElementById("email").value.toLowerCase(); var regex = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\ [[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/; ; if (regex.test(email)) { var temp = email.substring(email.lastIndexOf("@")+1); if (temp != "msu.edu") { alert("Enter correct email"); } } }