function calculate_price() {
  var k = document.forms['payment'];
  var base_p = Math.abs(k.elements['base_price'].value);
  var desc = k.elements['description'].value;
  var model_no = k.elements['model_no'].value;
  
 
  for (x = 0; x < k.elements['check_hdmi'].length; x++) {
    if ( k.elements['check_hdmi'][x].checked ) {
      base_p += Math.abs(k.elements['check_hdmi'][x].value);
      if (x==1) {
        model_no += '+1.2m+HDMI';
      } else if (x==2) {
        model_no += '+2.4m+HDMI';
      } else if (x==3) {
        model_no += '+5.0m+HDMI';
      }
    }
  }

  for (x = 0; x < k.elements['tick_delivery'].length; x++) {
    if ( k.elements['tick_delivery'][x].checked ) {
      base_p += Math.abs(k.elements['tick_delivery'][x].value);
      if (x == 0) {
        desc += '+Free+Delivery';
      } else if (x==1) {
        desc += '+Express+Delivery';
      } else if (x==2) {
        desc += '+Saturday+Delivery';
      } else if (x==3) {
        desc += '+Euro+Delivery';
      } 
    }
  }
  //alert(k.elements['discount'].value);return;

//John's Disc Code - Just Change the % and Codes

  if ( k.elements['discount'].value == 'PATCH' ) {
	base_p -= (base_p * .10);
        desc += '+DC:';
	desc += k.elements['discount'].value;
	} else if ( k.elements['discount'].value == 'patch' ) {
	base_p -= (base_p * .10);
        desc += '+DC:';
	desc += k.elements['discount'].value;
	} else if ( k.elements['discount'].value == 'AVFDISC' ) {
	base_p -= (base_p * .07);
        desc += '+DC:';
	desc += k.elements['discount'].value;
	} else if ( k.elements['discount'].value == 'avfdisc' ) {
	base_p -= (base_p * .07);
        desc += '+DC:';
	desc += k.elements['discount'].value;
	} else if ( k.elements['discount'].value == 'FPDISC' ) {
	base_p -= (base_p * .05);
        desc += '+DC:';
	desc += k.elements['discount'].value;
	}  else if ( k.elements['discount'].value == 'fpdisc' ) {
	base_p -= (base_p * .05);
        desc += '+DC:';
	desc += k.elements['discount'].value;
	}
  
  var email = 'nochex@standland.co.uk';
  var q = new String('https://secure.nochex.com/?email=' + email);
  q += '&amount=' + Math.round(base_p * 100) / 100;
  q += '&description=' + model_no + desc;
  
  document.location.href=q;
}