/********************************
*    shopping cart functions    *
********************************/

// saves the value entered in the qty field
function save(intID, strEl) {

    var re  = new RegExp("^[0-9]+$", 'i');
    var frm = document.forms[0];
    var tmp = frm.elements['Qty_'+intID];
    
    if( ! re.test(tmp.value) ) {
    
        alert('Invalid Quantity');
        tmp.value = '';
        tmp.focus();
        return;
    
    }
    
    frm.elements['action'].value = 'update';
    frm.elements['ID'].value = intID;
    frm.elements['Qty'].value = tmp.value;
    frm.submit();

}

// increases the qty of an item by 1
function addOne(intID) {

    var frm = document.forms[0];
    
    frm.elements['action'].value = 'addOne';
    frm.elements['ID'].value = intID;
    frm.elements['Qty'].value = 1;
    frm.submit();

}

// decreases the qty of an item by 1
function removeOne(intID) {

    var frm = document.forms[0];
    
    frm.elements['action'].value = 'removeOne';
    frm.elements['ID'].value = intID;
    frm.elements['Qty'].value = 1;
    frm.submit();

}

// removes an item from the cart altogether
function remove(intID) {

    var frm = document.forms[0];
    
    frm.elements['action'].value = 'removeProduct';
    frm.elements['ID'].value = intID;
    frm.elements['Qty'].value = 0;
    frm.submit();

}

// removes all items from the shopping cart
function ClearCart() {

    var frm = document.forms[0];
    frm.elements['action'].value = 'ClearCart';

}