/*
Strip whitespace from the beginning and end of a string
Input : a string
*/
function trim(str)
{
	return str.replace(/^\s+|\s+$/g,'');
}

/*
Make sure that textBox only contain number
*/
function checkNumber(textBox)
{
	while (textBox.value.length > 0 && isNaN(textBox.value)) {
		textBox.value = textBox.value.substring(0, textBox.value.length - 1)
	}
	
	textBox.value = trim(textBox.value);
/*	if (textBox.value.length == 0) {
		textBox.value = 0;		
	} else {
		textBox.value = parseInt(textBox.value);
	}*/
}

/*
	Check if a form element is empty.
	If it is display an alert box and focus
	on the element
*/
function isEmpty(formElement, message) {
	formElement.value = trim(formElement.value);
	
	_isEmpty = false;
	if (formElement.value == '') {
		_isEmpty = true;
		alert(message);
		formElement.focus();
	}
	
	return _isEmpty;
}

/*
	Set one value in combo box as the selected value
*/
function setSelect(listElement, listValue)
{
	for (i=0; i < listElement.options.length; i++) {
		if (listElement.options[i].value == listValue)	{
			listElement.selectedIndex = i;
		}
	}	
}

function AbrirCentrado(Url,NombreVentana,width,height,extras) {
	var largo = width;
	var altura = height;
	var adicionales= extras;
	//alert (adicionales);
	var top = (screen.height-altura)/2;
	var izquierda = (screen.width-largo)/2; 
	//nuevaVentana=window.open(''+ Url + '',''+ NombreVentana + '','width=' + largo + ',height=' + altura + ',top=' + top + ',left=' + izquierda + ',features=' + adicionales + ''); 
	nuevaVentana=window.open(''+ Url + '',''+ NombreVentana + '','width=' + largo + ',height=' + altura + ',top=' + top + ',left=' + izquierda + ',' + adicionales + ''); 
	nuevaVentana.focus();
}

<!-- Changes:  Sandeep V. Tamhankar (stamhankar@hotmail.com) -->

/* 1.1.2: Fixed a bug where trailing . in e-mail address was passing
            (the bug is actually in the weak regexp engine of the browser; I
            simplified the regexps to make it work).
   1.1.1: Removed restriction that countries must be preceded by a domain,
            so abc@host.uk is now legal.  However, there's still the 
            restriction that an address must end in a two or three letter
            word.
     1.1: Rewrote most of the function to conform more closely to RFC 822.
     1.0: Original  */

<!-- This script and many more are available free online at -->
<!-- The JavaScript Source!! http://javascript.internet.com -->

<!-- Begin
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("El correo luce incorrecto (revisa la @ y los .'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("El nombre de Usuario no es valido.")
    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("La Ip destino no es valida!")
		return false
	    }
    }
    return true
}

// Domain is symbolic name
var domainArray=domain.match(domainPat)
if (domainArray==null) {
	//alert("El dominio del correo no parece valido.")
    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;

}
//  End -->