function clearForm() 
{
	document.tilmelding.navn.value = "";
}

function vipCheck (passStr) {

// Her checkes om password er rigtigt

  if (passStr!="oak")
     {
        alert("Password er forkert!")
        return(false)
     }
     return true;
}

function passCheck (emailStr, navnStr) {


// Her checkes om navn og password er rigtigt

  if (navnStr!="carsten")
 
     {
        alert("Navnet er forkert")
        return(false)
     }

  if (emailStr!="stemning")
 
     {
        alert("Password er forkert")
        return(false)
     }
    return true;
}
	 
function formCheck (emailStr, navnStr) {


// Her checkes om alle felter er udfyldt: 

  if (navnStr=="")
 
     {
        alert("Udfyld felterne i formularen som er markeret med *")
        return(false)
     }

  if (emailStr=="")
 
     {
        alert("Udfyld felterne i formularen som er markeret med *")
        return(false)
     }
	 

// Her checkes om der er brugt semikolon i indtastningen:

    var iChars = ";";
       
    for (var i = 0; i < navnStr.length; i++) 
      {
  	    if (iChars.indexOf(navnStr.charAt(i)) != -1) 
  	      {
  	        alert ("I registreringsfelterne må ikke bruges semikolon.");
  	        return false;
  	      }
       }
       
     for (var i = 0; i <emailStr.length; i++) 
      {
  	    if (iChars.indexOf(emailStr.charAt(i)) != -1) 
  	      {
  	        alert ("I registreringsfelterne må ikke bruges semikolon.");
  	        return false;
  	      }
       }

// Her checkes en masse andet - læs mere i kommentarerne hvis du har tid:


    /* 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("Der er fejl i e-mailadressen.")
    	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("Der er fejl i e-mailadressen.")
        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("Der er fejl i e-mailadressen.")
    		return false
    	    }
        }
        return true
    }
    
    // Domain is symbolic name
    var domainArray=domain.match(domainPat)
    if (domainArray==null) {
    	alert("Der er fejl i e-mailadressen.")
        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>4) {
       // the address must end in a two letter or four letter word.
       alert("Der er fejl i e-mailadressen.")
       return false
    }
    
    if (len<2) {
       var errStr="Der er fejl i e-mailadressen."
       alert(errStr)
       return false
    }
    
    return true;
}