var whitespace = " \t\n\r";


// Check whether string s is empty.

function isEmpty(s)
{   return ((s == null) || (s.length == 0))
}

function isWhitespace (s)

{   var i;

    // Is s empty?
    if (isEmpty(s)) return true;

    // Search through string's characters one by one
    // until we find a non-whitespace character.
    // When we do, return false; if we don't, return true.

    for (i = 0; i < s.length; i++)
    {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);

        if (whitespace.indexOf(c) == -1) return false;
    }

    // All characters are whitespace.
    return true;
}


function validateForm(thisform){

	if (isWhitespace(thisform.firstname.value) )
	{
		alert("Please enter your first name...");
		thisform.firstname.select();
		thisform.firstname.focus();
		return false;
	}
	
		else if (isWhitespace(thisform.lastname.value))
	{
		alert("Please enter your last name...");
		thisform.lastname.select();
		thisform.lastname.focus();
		return false;
	}
	
		else if (isWhitespace(thisform.streetaddress.value) )
	{
		alert("Please enter your street address name...");
		thisform.streetaddress.select();
		thisform.streetaddress.focus();
		return false;
	}
	
		else if (isWhitespace(thisform.place.value) )
	{
		alert("Please enter your town or city...");
		thisform.place.select();
		thisform.place.focus();
		return false;
	}
	
	
	else if (isEmail(thisform.Email.value) == false) {
		alert("Please enter a valid e-mail address...");
		thisform.Email.select();
		thisform.Email.focus();
		return false;
	}
	

		else if (isWhitespace(thisform.CardNumber.value) )
	{
		alert("Please enter your credit card number...");
		thisform.CardNumber.select();
		thisform.CardNumber.focus();
		return false;
	}
	
		else if (isWhitespace(thisform.CardHolderName.value) )
	{
		alert("Please enter your card-holder name...");
		thisform.CardHolderName.select();
		thisform.CardHolderName.focus();
		return false;
	}
	
		else if (    
					(
						(theDate.getYear() == thisform.ExpYr.options[thisform.ExpYr.selectedIndex].value)
					 && (theDate.getMonth()+1 > thisform.ExpMo.options[thisform.ExpMo.selectedIndex].value) 
					 )
					    
					 || (theDate.getYear() > thisform.ExpYr.options[thisform.ExpYr.selectedIndex].value)       
					 
				)
	{	
		alert("That is not valid credit card expiry date...");
		return false;
	}
	
	
	
}




function isEmail(string) {
    if (string.search(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/) != -1)
        return true;
    else
        return false;
}

	 
function validate(string) {
    if (!string) return false;
    var Chars = "()-0123456789. ";

    for (var i = 0; i < string.length; i++) {
       if (Chars.indexOf(string.charAt(i)) == -1)
          return false;
    }
    return true;
}

function bookChosen(thisForm){

	if(
	thisForm.book1.checked == false &&
	thisForm.book2.checked == false &&
	thisForm.book3.checked == false &&
	thisForm.book4.checked == false &&
	thisForm.book5.checked == false &&
	thisForm.book6.checked == false &&
	thisForm.book7.checked == false &&
	thisForm.book8.checked == false &&
	thisForm.book9.checked == false &&
	thisForm.book10.checked == false &&
	thisForm.book11.checked == false &&
	thisForm.book12.checked == false &&
	thisForm.book13.checked == false &&
	thisForm.book14.checked == false &&
	thisForm.book15.checked == false
	)
	
	
	
	
	{
	alert ("You have not chosen a book...")
		return false;
	}else{
	
	return true;
	}

}