function emailCheck (emailStr) {
	/* 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("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
	}
	/* domain name seems valid, but now make sure that it ends in a
	three-letter word (like com, edu, gov) or a two-letter word,
	representing country (uk, nl), 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>3) {
		// 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 a hostname!"
		//alert(errStr)
		return false
	}
	// If we've gotten this far, everything's valid!
	return true;
}
function checkContent(f){
	var field_name=f.name;
	if(f.value==""){
		alert ("the "+field_name+" field must not be blank");
		document.getElementById(field_name).style.color="red";
		event.returnValue=false;
	}else document.getElementById(field_name).style.color="blue";
}
function checkConditions(f){
	if(!f.checked){
		alert ("the "+f.name+" box must be ticked");
		event.returnValue=false;
	}
}
function check_required(f,id){
	if(f.value==""){
		setStyleById(id,"color","#ff0000");
		return false;
	}
	else{
		setStyleById(id,"color","#000000");
		return true;
	}
}
function setStyleById(i, p, v) {
	var n = document.getElementById(i);
	n.style[p] = v;
}
function check_form(f){
	setStyleById("fb","color","#a0d7ec");
	var result1=check_required(f.email,"email");
	var result12=emailCheck(f.email.value);
	if(result12==false){
		setStyleById("fa","color","#ff0000");
		setStyleById("email","color","#ff0000");
	}else setStyleById("fa","color","#a0d7ec");
	var result2=check_required(f.full_name,"full_name");
	var result3=check_required(f.query,"query");
	if(result1 && result2 && result3 && result12)return true;
	else {
		if(!result1 || !result2 || !result3)setStyleById("fb","color","#ff0000"); 
		return false;
	}
}
function formReset(f){
	f.query.style.color='#707070';
	setStyleById("fa","color","#a0d7ec");
	setStyleById("fb","color","#a0d7ec");
	setStyleById("email","color","#000000");
	setStyleById("full_name","color","#000000");
	setStyleById("query","color","#000000");
}
function formSubmit(f){
	if(clickedCancel){
		clickedCancel=false;
		return true;
	}else{var checkResult=check_form(f);setPanel();return checkResult;}
}