Telephone and Email form validation, javascript

Include these javascript functions to your code.
Remember : Replace the ToDo parts correctly in your code.
Also, for valid phone number format you may have to search for a correct Phone Number regular expression (here i have included expression for a 3-4 number format).

Suppose your web page collects a customer's seven-digit phone number and you want to verify that the phone number is in the correct format, "xxx-xxxx", where each "x" is a digit. The following expression will search through text looking for such a string:

/* Regular Expression to validate the Phone Number format. */
        var validPhoneNumber = \b\d{3}-\d{4};

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<script language="javascript" type="text/javascript">

    /*Javascript function validating a Text Box input for a valid E-Mail address. */
    function IsValidEMail() 
    {
        /* ToDo : Please replace the name of your EMail Control with txtEMail here.*/
        var email = document.getElementById("<%=txtEMail.ClientID %>").value;
        
        /* Regular Expression to validate the EMail address format. */
        var validEMail = /^[\w\-\.\+]+\@[a-zA-Z0-9\.\-]+\.[a-zA-z0-9]{2,4}$/;

        var gotItCorrect = email.match(validEMail);

        /* If the EMail is not correct */
        if (!gotItCorrect) {

            alert("Please enter a valid E-Mail (of format xxx@yyy.zzz).");

            /* ToDo : Please replace the name of your EMail Control with txtEMail here.*/
            document.getElementById("<%=txtEMail.ClientID %>").focus();
            return false;
        }
        else {
            return true;
        }
    }

    /*Javascript function validating a Text Box input for a valid Phone Number. */
    function IsValidPhoneNumber () {
        /* ToDo : Please replace the name of your PhoneNumber Control with txtPhoneNumber here.*/
        var phoneNumber = document.getElementById("<%=txtPhoneNumber.ClientID %>").value;

        /* ToDo : Regular Expression to validate the Phone Number format. */
        var validPhoneNumber = \b\d{3}-\d{4};

        var gotItCorrect = phoneNumber.match(validPhoneNumber);

        /* If the EMail is not correct */
        if (!gotItCorrect) {

            alert("Please enter a valid Phone Number.");

            /* ToDo : Please replace the name of your EMail Control with txtEMail here.*/
            document.getElementById("<%=txtPhoneNumber.ClientID %>").focus();
            return false;
        }
        else {
            return true;
        }
    }

</script>

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Please use the CODE button or [ code ] tags.


I have edited your posts to wrap the code in [ code] [/ code]

manch: I suggest you do not alert in your function and instead change

var gotItCorrect = email.match(validEMail);

        /* If the EMail is not correct */
        if (!gotItCorrect) {

            alert("Please enter a valid E-Mail (of format xxx@yyy.zzz).");

            /* ToDo : Please replace the name of your EMail Control with txtEMail here.*/
            document.getElementById("<%=txtEMail.ClientID %>").focus();
            return false;
        }
        else {
            return true;
        }

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to

  return email.match(validEMail);

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and have the calling function take care of display

Also your phone number RegEx is not valid

Thank you mplungjan, very detailed and helpful to follow.  I am getting a script error though stating that TypeError: (intermediate value).match is not a function.

I'll test in jsfiddle tomorrow

Okay, that works.  But I am trying to get the Phone number to not be required but still be validated.  Everything I am trying is not working.  This was my last attempt...

   if (chkFNm == "") {
      chk++;
      chkArray[chk] = "A valid 'user first name' is required";}
   if (chkLNm == "") {
      chk++;
      chkArray[chk] = "A valid 'user last name' is required";}
   if (chkComPhn == !isValidPhone(chkComPhn)) {
      chk++;
      chkArray[chk] = "A valid 'telephone' is required";}
   if (chkComEml == "" || !isValidEmail(chkComEml)) {
      chk++;
      chkArray[chk] = "A valid 'email address' is required";}
   if (chkTZone == "") {
      chk++;
      chkArray[chk] = "A valid 'user time zone' selection is required";}	  
   if (chkFacID == "") {
      chk++;
      chkArray[chk] = "A valid 'facility' selection is required";}
   if (chkRole == "") {
      chk++;
      chkArray[chk] = "A valid 'role' selection is required";}
   if (chk > 0) {
      var chk_txt = "Errror! The form cannot be submitted due to the following:\n\n";
      for (c = 1; c <= chk; c++) {
         chk_txt = chk_txt + c + ") " + chkArray[c] + "\n";}
      alert(chk_txt);}

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