////////////////////////////////////////////////////////////////

// Grab the selected value from a <select> tag.

function getOptionValue(field)

{	var index = field.selectedIndex;

	return field.options[index].value;

}



////////////////////////////////////////////////////////////////

// Gets rid of the pesky outline when you click an image link.

function clearme()

{	window.focus();

}



////////////////////////////////////////////////////////////////

// Image Rollover Functions

function rover(target, newSrc)

{	if(document.images[target])

		document.images[target].src = newSrc;

}



////////////////////////////////////////////////////////////////

// For error handling, msg is the error message to the user.

// fieled is the offending field object.

function errAlert(msg, field)

{	alert(msg);

	field.focus();

	if(field != window)

	{	if(field.type == "text")

			field.select();

	}

}



////////////////////////////////////////////////////////////////

// For validation, returns true if string val is only digits

function isNumber(val)

{	for (i = 0; i < val.length; i++)

	{	// Check that current character is number.

		var c = val.charAt(i);

		if ((c >= "0") && (c <= "9"))

			return true;

		else

			return false;

    }

}



// isEmail (STRING s [, BOOLEAN emptyOK])

// 

// Email address must be of form a@b.c -- in other words:

// * there must be at least one character before the @

// * there must be at least one character before and after the .

// * the characters @ and . are both required

function isEmail (s)

{  

	/* 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=s.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;

}



////////////////////////////////////////////////////////////////

// Open a pop-up window containing URL.

// Window arguments are organized for easy changing.  Maybe later

// this will allow the window arguments to be set by parameters.

function popwin(URL)

{	var size = "height=300,width=550"; //This always comes first, so all others begin with comma

	var XY = ",screenX=20,screenY=20";

	var hide = ",directories=no,location=no,menubar=no,toolbar=no";

	var show = ",titlebar=yes";

	var resize = ",resizable=yes";

	window.open(URL, "child", size+XY+hide+show+resize);

}