if (document.images)
{
nav_1_up = new Image;
nav_1_over = new Image;
nav_1_up.src ="images/nav_1_up.gif";
nav_1_over.src ="images/nav_1_over.gif";

nav_2_up = new Image;
nav_2_over = new Image;
nav_2_up.src ="images/nav_2_up.gif";
nav_2_over.src ="images/nav_2_over.gif";

nav_3_up = new Image;
nav_3_over = new Image;
nav_3_up.src ="images/nav_3_up.gif";
nav_3_over.src ="images/nav_3_over.gif";

nav_4_up = new Image;
nav_4_over = new Image;
nav_4_up.src ="images/nav_4_up.gif";
nav_4_over.src ="images/nav_4_over.gif";

nav_5_up = new Image;
nav_5_over = new Image;
nav_5_up.src ="images/nav_5_up.gif";
nav_5_over.src ="images/nav_5_over.gif";

nav_6_up = new Image;
nav_6_over = new Image;
nav_6_up.src ="images/nav_6_up.gif";
nav_6_over.src ="images/nav_6_over.gif";

nav_7_up = new Image;
nav_7_over = new Image;
nav_7_up.src ="images/nav_7_up.gif";
nav_7_over.src ="images/nav_7_over.gif";

nav_8_up = new Image;
nav_8_over = new Image;
nav_8_up.src ="images/nav_8_up.gif";
nav_8_over.src ="images/nav_8_over.gif";

nav_9_up = new Image;
nav_9_over = new Image;
nav_9_up.src ="images/nav_9_up.gif";
nav_9_over.src ="images/nav_9_over.gif";

nav_10_up = new Image;
nav_10_over = new Image;
nav_10_up.src ="images/nav_10_up.gif";
nav_10_over.src ="images/nav_10_over.gif";

}
else

{ // for non  javascript browsers

nav_1_up = "";
nav_2_up = "";
nav_3_up = "";
nav_4_up = "";
nav_5_up = "";
nav_6_up = "";
nav_7_up = "";
nav_8_up = "";
nav_9_up = "";
nav_10_up = "";

nav_1_over = "";
nav_2_over = "";
nav_3_over = "";
nav_4_over = "";
nav_5_over = "";
nav_6_over = "";
nav_7_over = "";
nav_8_over = "";
nav_9_over = "";
nav_10_over = "";

document.one = "";
document.two = "";
document.three = "";
document.four = "";
document.five = "";
document.six = "";
document.seven = "";
document.eight = ""
document.nine = ""
document.ten = ""
}

<!-- form validation -->

/*function validate()
{
  	
	if (document.myform.Requestor_RegistrationType.value == "") {
        alert( "Please select Registration Type." );
        document.myform.Requestor_RegistrationType.focus();
        return false ;
		}
		else
		{
	
	if (document.myform.Requestor_WhyAttending.value == "") {
        alert( "Please select why you are attending." );
        document.myform.Requestor_WhyAttending.focus();
        return false ;
		}
		else
		{
	
	if (document.myform.Name_UnisysRep.value == "") {
        alert( "Please enter the name of your Unisys sales representative." );
        document.myform.Name_UnisysRep.focus();
        return false ;
		}
		else
		{	

	if (document.myform.Name_Salutation.value == "") {
        alert( "Please select a salutation." );
        document.myform.Name_Salutation.focus();
        return false ;
		}
		else
		{
	
	if (document.myform.FirstName.value == "") {
        alert( "Please enter your first name." );
        document.myform.FirstName.focus();
        return false ;
		}
		else
		{

	if (document.myform.LastName.value == "") {
        alert( "Please enter your last name." );
        document.myform.LastName.focus();
        return false ;
		}
		else
		{

	if (document.myform.JobTitle.value == "") {
        alert( "Please enter your job title." );
        document.myform.JobTitle.focus();
        return false ;
		}
		else
		{
	
	if (document.myform.Telephone_CountryCode.value == "") {
        alert( "Please enter the country code for your telephone number." );
        document.myform.Telephone_CountryCode.focus();
        return false ;
		}
		else
		{
			
	if (document.myform.Telephone_AreaCode.value == "") {
        alert( "Please enter the area code for your telephone number." );
        document.myform.Telephone_AreaCode.focus();
        return false ;
		}
		else
		{
			
	if (document.myform.Telephone_LocalNumber.value == "") {
        alert( "Please enter your local phone number." );
        document.myform.Telephone_LocalNumber.focus();
        return false ;
		}
		else
		{
			
	if ((document.myform.email.value.indexOf("@") == -1 ) ||
        (document.myform.email.value.indexOf(".") == -1 )) {
        alert("Please enter a valid email address");
		document.myform.email.focus();
        return false ;
		}
		else
		{
			
	if (document.myform.AttendingOn14th.checked == false &&
  		document.myform.AttendingOn15th.checked == false &&
  		document.myform.AttendingOn16th.checked == false &&
  		document.myform.AttendingOn17th.checked == false) 
        {
        alert( "Please select at least one date that you will be attending." );
        document.myform.AttendingOn14th.focus();
        return false ;
        }
  		else
		{

			
	if (document.myform.Shirtsize.value == "") {
        alert( "Please select your shirt size." );
        document.myform.Requestor_Shirtsize.focus();
        return false ;
		}
		else
		{
			
	if (document.myform.Companyname.value == "") {
        alert( "Please enter your company name." );
        document.myform.Companyname.focus();
        return false ;
		}
		else
		{
			
	if (document.myform.Address_1.value == "") {
        alert( "Please enter your PO Box No. or Street No. and Street Name where you work." );
        document.myform.Address_1.focus();
        return false ;
		}
		else
		{
			
	if (document.myform.Address_2.value == "") {
        alert( "Please enter the suburb where you work." );
        document.myform.Address_1.focus();
        return false ;
		}
		else
		{
			
	if (document.myform.Address_3.value == "") {
        alert( "Please enter the city where you work." );
        document.myform.Address_1.focus();
        return false ;
		}
		else
		{
			
	if (document.myform.Address_4.value == "") {
        alert( "Please enter the country where you work." );
        document.myform.Requestor_Address_4.focus();
        return false ;
		}
		else
		{
	
	return true ;
	}
*/