function block(nr) {
	if (document.layers) {
		current = (document.layers['m'+nr].display == 'none') ? 'block' : 'none';
		document.layers['m'+nr].display = current;
	}
	else if (document.all) {
		current = (document.all['m'+nr].style.display == 'none') ? 'block' : 'none';
		document.all['m'+nr].style.display = current;
	}
	else if (document.getElementById) {
		current = (document.getElementById('m'+nr).style.display == 'none') ? 'block' : 'none';
		document.getElementById('m'+nr).style.display = current;
	}
}
function validate(emailStr) {
	var emailPat=/^(.+)@(.+)$/
	var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]"
	var validChars="\[^\\s" + specialChars + "\]"
	var quotedUser="(\"[^\"]*\")"
	var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/
	var atom=validChars + '+'
	var word="(" + atom + "|" + quotedUser + ")"
	var userPat=new RegExp("^" + word + "(\\." + word + ")*$")
	var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$")

	var matchArray=emailStr.match(emailPat)
	if (matchArray==null) {
		alert("E-mail seems to be wrong (check @ and .'s)")
		return false
	}
	var user=matchArray[1]
	var domain=matchArray[2]
	if (user.match(userPat)==null) {
	    alert("Your name in the e-mail meens to be wrong.")
	    return false
	}
	var IPArray=domain.match(ipDomainPat)
	if (IPArray!=null) {
		for (var i=1;i<=4;i++) {
		  if (IPArray[i]>255) {
	      alert("Destination IP address is wrong!")
				return false
		  }
	  }
	  return true
	}
	var domainArray=domain.match(domainPat)
	if (domainArray==null) {
		alert("The domainname in the e-mail i wrong.")
	  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) {
		alert("Please check the e-mail again")
		return false
	}
	if (len<2) {
		var errStr="The e-mail is missing a hostname!"
		alert(errStr)
		return false
	}
}