/******************************************************
	FUNCTIONS TO DISPLAY A RANDOM IMAGE
******************************************************/
function random_image() {
var randomImages = [
"images/subheader-home.jpg",
"images/subheader-02.jpg",
"images/subheader-03.jpg",
"images/subheader-04.jpg"
];
document.images['random_image'].src = randomImages[Math.floor(Math.random() * randomImages.length)];
};
/******************************************************/

/******************************************************
	FUNCTIONS TO EMPTY AND RE-FILL A TEXT FIELD
******************************************************/
function clickclear(thisfield, defaulttext) {
	if (thisfield.value == defaulttext) {
	thisfield.value = "";
	}
}

function clickrecall(thisfield, defaulttext) {
	if (thisfield.value == "") {
	thisfield.value = defaulttext;
	}
}
/******************************************************/

/******************************************************
	FUNCTION TO ALLOW ONLY NUMBERS IN A TEXTFIELD
******************************************************/
<!--
// copyright 1999 Idocs, Inc. http://www.idocs.com
// Distribute this script freely but keep this notice in place
function numbersonly(myfield, e, dec)
{
var key;
var keychar;

if (window.event)
   key = window.event.keyCode;
else if (e)
   key = e.which;
else
   return true;
keychar = String.fromCharCode(key);

// control keys
if ((key==null) || (key==0) || (key==8) || 
    (key==9) || (key==13) || (key==27) )
   return true;

// numbers
else if ((("0123456789").indexOf(keychar) > -1))
   return true;

// decimal point jump
else if (dec && (keychar == "."))
   {
   myfield.form.elements[dec].focus();
   return false;
   }
else
   return false;
}

//-->

/******************************************************
	FUNCTION TO VALIDATE A GIVEN EMAIL ADDRESS
******************************************************/

function echeck(str) {

		var at="@"
		var dot="."
		var lat=str.indexOf(at)
		var lstr=str.length
		var ldot=str.indexOf(dot)
		if (str.indexOf(at)==-1){
		   return false
		}

		if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
		   return false
		}

		if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
		    return false
		}

		 if (str.indexOf(at,(lat+1))!=-1){
		    return false
		 }

		 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
		    return false
		 }

		 if (str.indexOf(dot,(lat+2))==-1){
		    return false
		 }
		
		 if (str.indexOf(" ")!=-1){
		    return false
		 }

 		 return true					
	}

/******************************************************
	FUNCTION TO VALIDATE A GIVEN EMAIL ADDRESS
******************************************************/

function validate_email(field,alerttxt)
{
with (field)
{
apos=value.indexOf("@");
dotpos=value.lastIndexOf(".");
if (apos<1||dotpos-apos<2) 
  {alert(alerttxt);return false;}
else {return true;}
}
}