It consists of 2 functions one of which contains boolean variable set to true or false and the other expands it a bit.
It uses the event handler onSubmit in the form where the email field is placed.
I'll give some later commments in red as we go along.
|
<script Language="JavaScript">
function isEmailAddr(email)
{
var result = false
/*
This is a boolean variable that will be set to true or false later in the function
*/
var theStr = new String(email)
var index = theStr.indexOf("@");
/*
It gives the name for the entire email string and the substring of the email string starting from symbol "@"
*/
if (index > 0)
{
var dot = theStr.indexOf(".",index);
if ((dot > index+2) && (theStr.length > dot+2))
result = true;
}
return result;
}
/*
If "@" symbol exists in the main string it then identifies that part of the "@" substring that starts from "." symbol. If there's at least 2 symbols after "@" and at least 2 after "." it sets the boolean variable to true. If anything is not as specified above - then the function is boolean false
*/
function FormValidator(theForm)
{
if (theForm.email.value == "")
{
alert("Please enter a value for the \"email\" field.");
theForm.email.focus();
return (false);
}
/*
This part checks if the email field is blank. If it is it gives an alert message
*/
if (!isEmailAddr(theForm.email.value))
{
alert("Please enter a complete email address in the form: yourname@yourdomain.com");
theForm.email.focus();
return (false);
}
/*
This part checks if the first function is false. if it is it then gives an alert message and points the cursor back to the field.
*/
return (true);
}
</script> |
This is the code you'll need to insert in the body of your html page:
<form method="POST" action="some server side script to go with JS" onsubmit="return FormValidator(this)">
<p>Email Address:</p> <input type="text" style="background-color:'#fff00f'" name="email" size="32"><input type="submit"
value="Submit" name="submit">
</form> |
Please note that this script should work with a respective server-side script indicated in "action" to store email addresses in the database for instance. Happy coding!
