//Methode check if E-mail adress has valid format
//InputParam:
//	emailStr: The E-mail address to be checked
//	error1 to error6: If all blank, default message will appear.
//		If Only error1 has text this message will apear for all error situations
//		By defining text for each error param, 6 different messages will appear
//			according to where the E-mail adress is not valid 
//Return: Boolean

function emailCheck (emailStr, error1, error2, error3,error4,error5,error6) {

	var commentsEmailArray = new Array(6)

	if (error1 == ""){
		commentsEmailArray[0]= "Ugyldig E-mail adresse"
		commentsEmailArray[1]= "Ugyldig E-mail adresse"
		commentsEmailArray[2]= "Ugyldig E-mail adresse"
		commentsEmailArray[3]= "Ugyldig E-mail adresse"
		commentsEmailArray[4]= "Ugyldig E-mail adresse"
		commentsEmailArray[5]= "Ugyldig E-mail adresse"
	}

	else if (error2 == "" && error3 == "" && error4 == "" && error5 == "" && error6){
		commentsEmailArray[0]=error1
		commentsEmailArray[1]=error1
		commentsEmailArray[2]=error1
		commentsEmailArray[3]=error1
		commentsEmailArray[4]=error1
		commentsEmailArray[5]=error1
	}
	else{
		commentsEmailArray[0]=error1
		commentsEmailArray[1]=error2
		commentsEmailArray[2]=error3
		commentsEmailArray[3]=error4
		commentsEmailArray[4]=error5
		commentsEmailArray[5]=error6	
	}
	



	/* 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="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]"

	/* 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. "jiminy 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. joe@[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 john.doe@somewhere.com, john and doe 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(commentsEmailArray[0])
		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(commentsEmailArray[1])
	    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(commentsEmailArray[2])
			return false
		    }
	    }
	    return true
	}

	// Domain is symbolic name

	var domainArray=domain.match(domainPat)
	if (domainArray==null) {
		alert(commentsEmailArray[3])
	    return false
	}

	/* domain name seems valid, but now make sure that it ends in a
	   three-letter word (like com, edu, gov), a two-letter word 
	   representing country (uk, nl) or or a four-
	   letter word (like info) and that there's a hostname preceding
	   the domain or country. */

	/* Now we need to break up the domain to get a count of how many atoms
	   it consists of. */

	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>4) {
	   // the address must end in a two letter, three or four letter word.
	   alert(commentsEmailArray[4])
	   return false
	}

	// Make sure there's a host name preceding the domain.

	if (len<2) {
	   alert(commentsEmailArray[5])
	   return false
	}

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