/**
* function to enforce max limit on comment field and provide visual feedback
* - only a backup, actual field size is also truncated in php
*/
function textCounter(textField, countField, charlimit) {
	//fetch text field and limit field
	var objTextField  = document.getElementById(textField);
	var objCountField = document.getElementById(countField);
	
	if (objTextField.value.length > charlimit) {
		// if too long...trim it!
		objTextField.value = objTextField.value.substring(0, charlimit);
	} else {
		// otherwise, update 'characters left' counter
		objCountField.innerHTML = charlimit - objTextField.value.length;
	}
}

function updatePrice(qtyField, priceField, price, incVat)
{
    // get ref qty and price fields
	var qtyField   = document.getElementById(qtyField);
	var priceField = document.getElementById(priceField);
	
	// get actual value from field
	var qty = qtyField.value;
		
	// quantity is set?
	if(qty > 0)
	{
    	// calculate var on top of price?
    	if( incVat != null )
    	{
        	// calculate price including V.A.T
    	    priceIncVat = ( ( qty * price ) * 1.175 );
    	}
    	else
    	{
    	    // calculate price
    	    priceIncVat = ( qty * price );
	    }
    	
    	// display to 2 d.p
		priceField.value = priceIncVat.toFixed(2);
	}
	else
	{
		priceField.value = 0;
	}
}