function SubmitForm()
{
		if(!isValidEmail(document.regfrm.usremailn.value))
		     	{ 
			 	
			   		document.regfrm.usremailn.focus();
			   		return false;
				}	
	
    return true;
}

function isValidEmail(emailStr)
{
		if(emailStr=="")
		{
				alert("Please enter email id.");
				
				return false;
				
				
		}
			/* The following pattern is used to check if the entered e-mail address
			   fits the user@domain format.  It also is used to separate the username
			   from the domain. */
			var emailPat=/^(.+)@(.+)$/
			/* The following string represents the pattern for matching all special
			   characters.  We don't want to allow special characters in the address. 
			   These characters include ( ) < > @ , ; : \ " . [ ]    */
			//var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]"
			var specialChars="\\(\\)<>@,`';:~!#$%^&*+=|{}?\\\\\\\"\\.\\[\\]"
			
			/* The following string represents the range of characters allowed in a 
			   username or domainname.  It really states which chars aren't allowed. */
			var validChars="\[^\\s" + specialChars + "\]"
			/* The following pattern applies if the "user" is a quoted string (in
			   which case, there are no rules about which characters are allowed
			   and which aren't; anything goes).  E.g. "sg cricket"@disney.com
			   is a legal e-mail address. */
			var quotedUser="(\"[^\"]*\")"
			/* The following pattern applies for domains that are IP addresses,
			   rather than symbolic names.  E.g. sg@[123.124.233.4] is a legal
			   e-mail address. NOTE: The square brackets are required. */
			var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/
			/* The following string represents an atom (basically a series of
			   non-special characters.) */
			var atom=validChars + '+'
			/* The following string represents one word in the typical username.
			   For example, in sg.sg@somewhere.com, sg and sg are words.
			   Basically, a word is either an atom or quoted string. */
			var word="(" + atom + "|" + quotedUser + ")"
			// The following pattern describes the structure of the user
			var userPat=new RegExp("^" + word + "(\\." + word + ")*$")
			/* The following pattern describes the structure of a normal symbolic
			   domain, as opposed to ipDomainPat, shown above. */
			var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$")


			/* Finally, let's start trying to figure out if the supplied address is
			   valid. */

			/* Begin with the coarse pattern to simply break up user@domain into
			   different pieces that are easy to analyze. */
			var matchArray=emailStr.match(emailPat)
			if (matchArray==null)
			{
			  /* Too many/few @'s or something; basically, this address doesn't
			     even fit the general mould of a valid e-mail address. */
				alert("Email address seems incorrect (check @ and .'s)")
				return false
			}
			var user=matchArray[1]
			var domain=matchArray[2]

			// See if "user" is valid 
			if (user.match(userPat)==null)
			{
			    // user is not valid
			    alert("The username doesn't seem to be valid.")
			    return false
			}

			/* if the e-mail address is at an IP address (as opposed to a symbolic
			   host name) make sure the IP address is valid. */
			var IPArray=domain.match(ipDomainPat)
			if (IPArray!=null)
				{
			    // this is an IP address
				  for (var i=1;i<=4;i++)
					  {
						 if (IPArray[i]>255)
						{
				        alert("Destination IP address is invalid")
					return false
						}
					}
			    return true
			}

			// Domain is symbolic name
			var domainArray=domain.match(domainPat)
			if (domainArray==null)
				{
					alert("The domain name doesn't seem to be valid.")
					return false
				}

			
			var atomPat=new RegExp(atom,"g")
			var domArr=domain.match(atomPat)
			var len=domArr.length
			if (domArr[domArr.length-1].length<2 || 
			    domArr[domArr.length-1].length>5)
				{
					// the address must end in a two letter or three letter word.
					alert("The address must end in a three-letter domain, or two letter country.")
					return false
				}

			// Make sure there's a host name preceding the domain.
			if (len<2) 
				{
					var errStr="This address is missing hostname."
					alert(errStr)
					return false
				}

			// If we've gotten this far, everything's valid!
			return true;
}