function checkSignUp(){
un1.value=un1.value.toLowerCase()
un2.value=un2.value.toLowerCase()
if (emailCheck(un1.value)==false) return false
if (un1.value != un2.value){
alert("Email Addreses do not match");
return false;}
if (un1.value.substring(0,4)=='www.'){
alert('Email Addreses do not start with www.')
return false
}
if (ck.checked==false){
alert("To register you must check the terms of service!");
return false
}
return true
}
function checkRetrivePassword(){
un.value=un.value.toLowerCase();
if (emailCheck(un.value)==false) return false;
return true
}			
function checkEmail(s){
if (emailCheck(s.value)) return true;
else return false;
}
function emailCheck (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("Email address seems incorrect (check @ and .'s)")
return false
}
var user=matchArray[1]
var domain=matchArray[2]
if (user.match(userPat)==null){
alert("The username of the email address doesn't seem to be valid.")
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 invalid!")
return false
}
}
return true
}
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>4) {
alert("The email address must end in a three-letter domain, or two letter country.")
return false
}
if (len<2) {
var errStr="This address is missing a hostname!"
alert(errStr)
return false
}
return true;
}