// compareCruises.js
function validateCompareCruisesForm(compareform) {
	var minimumToCompare = 2;
	var selectedCruisesCount = getCheckboxCount(compareform);

	if (selectedCruisesCount < minimumToCompare)
		alert("Please select at least two checkboxes to compare cruises");
			
	return (selectedCruisesCount >= minimumToCompare);
}
	
function setButtonState(checkbox, compareform) {
	var maximumToCompare = 3;
	var selectedCruisesCount = getCheckboxCount(compareform);

	if (selectedCruisesCount > maximumToCompare) {
		alert("You may only compare up to " + maximumToCompare + " cruises ");
		checkbox.checked = false;
	}
}
	
function getCheckboxCount(compareform) {
	
	var selectedCruisesCount = 0
		
	if (compareform.compare != undefined && compareform.compare != null ) {
		
		for (var i=0; i < compareform.compare.length; i++) {
			if (compareform.compare[i].checked == true)
				selectedCruisesCount++ ;
		}
	}
		
	// read the hidden values			
	if (compareform.compareFromOtherPage != undefined) {
		if (compareform.compareFromOtherPage.length == undefined)
			selectedCruisesCount++ ;
		else
			for (var i=0; i < compareform.compareFromOtherPage.length; i++) {
				selectedCruisesCount++;
			}
	}
		
	return selectedCruisesCount
}