function checkban() {
	if (document.layers||document.all||document.getElementById)
		return checknumber()
	else return true;
}

function checknumber(){
		
	var a=document.frmAlcohol.txtBitterPint.value;
	var b=document.frmAlcohol.txtLagerPint.value;
	var c=document.frmAlcohol.txtLargeRed.value;
	var d=document.frmAlcohol.txtMediumRed.value;
	var e=document.frmAlcohol.txtSmallRed.value;
	var f=document.frmAlcohol.txtLargeWhite.value;
	var g=document.frmAlcohol.txtMediumWhite.value;
	var h=document.frmAlcohol.txtSmallWhite.value;
	var i=document.frmAlcohol.txtChampagne.value;
	var j=document.frmAlcohol.txtCiderPint.value;
	var k=document.frmAlcohol.txtVodka.value;
	var l=document.frmAlcohol.txtGin.value;
	var m=document.frmAlcohol.txtRum.value;
	var n=document.frmAlcohol.txtWhiskey.value;
	var o=document.frmAlcohol.txtBaileys.value;
	var p=document.frmAlcohol.txtSouthernComfort.value;
	var q=document.frmAlcohol.txtTiaMaria.value;
	var r=document.frmAlcohol.txtJackDaniels.value;
	var s=document.frmAlcohol.txtFizzy.value;
	var t=document.frmAlcohol.txtFruit.value;
	
	drinkList = new Array(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t);
	
	drinkUnitValues = new Array(64, 167, 170, 119, 85, 165, 116, 93, 95, 103, 50, 50, 50, 50, 81, 79, 66, 60, 50, 50);
	
	var anum=/(^\d+$)|(^\d+\.\d+$)/
	
	for (i=0; i<drinkList.length; i++) {
		if (!anum.test(drinkList[i]) && (drinkList[i] != "")) {
			alert("Please check that at least one field has been filled in and that the entry is a valid number!")
			return false;
		}
	}	
	
	return findSpend(drinkList, drinkUnitValues);
		

}

function findSpend(x) {

	var unitsConsumed = 0;

	for (i=0; i<drinkList.length; i++) {
		if (drinkList[i] == "") {
			drinkList[i] = 0;
			unitsConsumed += (drinkList[i] * drinkUnitValues[i]);
		} else {
			unitsConsumed += (drinkList[i] * drinkUnitValues[i]);
		}
	}
	return writeToFields(unitsConsumed);

}


function writeToFields(val) {

	//convert values to 2 dp
	newVal=parseInt((val*100))/100;
	
	document.frmAlcohol.txtCalories.value = newVal;
	return false;
}