//validates the form
function ValidateForm(ddlIsland, ddlRegion,  ddlPriceMin, ddlPriceMax) {

    var isValid = true;

    //validate island
    isValid = ValidateDropdownList('Please select island and region', '0', ddlIsland);
    if (!isValid) {
        return false;
    }

    //validate region
    isValid = ValidateDropdownList('Please select island and region', '0', ddlRegion);
    if (!isValid) {
        return false;
    }

   
    //validate price
    isValid = ValidateDropdownListRange('Price Min cannot be larger than Price Max', ddlPriceMin, ddlPriceMax, '0');
    if (!isValid) {
        return false;
    }

    

    return isValid;

}