Aleenanne : Reference :Java Code

Reference JavaScript Code Library

The IsEmailValid() routine tests whether the specified field of the given form contains an email address of valid syntax. As the actual email address cannot be truly verified without some special magic, this routine shall at least attempt to verify the syntax of the address.

If the given email address is not valid, an error is displayed, the focus is set back to the specified form element, and a value of FALSE is returned, otherwise a value of TRUE is returned.

Usage: IsEmailValid("FormName","ElemName")

Demo (All JavaScript browsers )

Cut, paste, and enjoy!

// -----------------------------------------------------------------
// Function    : IsEmailValid
// Language    : JavaScript
// Description : Checks if given email address is of valid syntax
// Copyright   : (c) 1998 Shawn Dorman
// -----------------------------------------------------------------
// Ver    Date    Description of modification
// --- ---------- --------------------------------------------------
// 1.0 09/04/1996 Original write
// 1.1 09/30/1998 CHG: Use standard header format
// -----------------------------------------------------------------

function IsEmailValid(FormName,ElemName)
{
var EmailOk  = true
var Temp     = document.forms[FormName].elements[ElemName]
var AtSym    = Temp.value.indexOf('@')
var Period   = Temp.value.lastIndexOf('.')
var Space    = Temp.value.indexOf(' ')
var Length   = Temp.value.length - 1   // Array is from 0 to length-1

if ((AtSym < 1) ||                     // '@' cannot be in first position
    (Period <= AtSym+1) ||             // Must be atleast one valid char btwn '@' and '.'
    (Period == Length ) ||             // Must be atleast one valid char after '.'
    (Space  != -1))                    // No empty spaces permitted
   {  
      EmailOk = false
      alert('Please enter a valid e-mail address!')
      Temp.focus()
   }
return EmailOk
}

// -->

</script>