function checkform(elementID) {

	var monthyear = document.forms[elementID].depMY.options[document.forms[elementID].depMY.selectedIndex].value;
	var month = monthyear.substr(0,2);
	var year = monthyear.substr(2,4);

  	var dateString = year+"/"+month+"/"+document.forms[elementID].depDay.value;
  	var myDate = new Date(dateString);
	var weekday=new Array(7);
	weekday[0]="Sunday";
	weekday[1]="Monday";
	weekday[2]="Tuesday";
	weekday[3]="Wednesday";
	weekday[4]="Thursday";
	weekday[5]="Friday";
	weekday[6]="Saturday";
	//alert(dateString);
	//alert(weekday[myDate.getDay()]);
	//alert(document.forms[elementID].destination.value);

	if(elementID==="pk"){
		if(document.forms[elementID].destination.selectedIndex == 0){
			alert("Please select a destination");
			return(false);
		}else if(document.forms[elementID].from.selectedIndex == 0){
			alert("Please select a departure airport");
			return(false);
		}else if(document.forms[elementID].depDay.options[document.forms[elementID].depDay.selectedIndex].value <= "12" && month <= "03" && year <= "2010") {
			alert("Please select a date in the future");
			return(false);
		} else if(weekday[myDate.getDay()]!="Tuesday" && document.forms[elementID].destination.value=="MLA" && (document.forms[elementID].from.value=="BRS" || document.forms[elementID].from.value=="EXT" || document.forms[elementID].from.value=="NWI" || document.forms[elementID].from.value=="CWL")){
			alert("Your chosen airport only operates a chartered flight to Malta on a Tuesday\n\nPlease re-select");
			return(false);
		} else if(document.forms[elementID].destination.value=="MLA" && (document.forms[elementID].from.value=="EMA")){
			return confirm("PLEASE NOTE: This route operates every Tuesday and Saturday as of 29th May 2010\n\nTo confirm your selection, press OK or press Cancel to reselect using Birmingham or Luton instead.");
		} else if(weekday[myDate.getDay()]!="Monday" && document.forms[elementID].destination.value=="FNC" && document.forms[elementID].plusminus.value!=1 && (document.forms[elementID].from.value=="BHX" || document.forms[elementID].from.value=="BOH" || document.forms[elementID].from.value=="CWL" || document.forms[elementID].from.value=="EMA" || document.forms[elementID].from.value=="EDI" || document.forms[elementID].from.value=="EXT" || document.forms[elementID].from.value=="GLA" || document.forms[elementID].from.value=="LTN" || document.forms[elementID].from.value=="MAN")){
			alert("Your chosen airport only operates a chartered flight to Madeira on a Monday\n\nPlease re-select");
			return(false);
		} else if(weekday[myDate.getDay()]!="Tuesday" && document.forms[elementID].destination.value=="MLA" && (document.forms[elementID].from.value=="EMA")){
			alert("Your chosen airport only operates a chartered flight to Malta on a Tuesday\n\nPlease re-select");
			return(false);
		}else if(document.forms[elementID].r1ad.value == 1 & document.forms[elementID].r1ch.value > 0){
			alert("Room 1: Occupancy rules restrict children from sharing with a single adult.");
			return(false);
		}else if(document.forms[elementID].r2ad.value == 1 & document.forms[elementID].r2ch.value > 0){
			alert("Room 2: Occupancy rules restrict children from sharing with a single adult.");
			return(false);
		}else if(document.forms[elementID].r3ad.value == 1 & document.forms[elementID].r3ch.value > 0){
			alert("Room 3: Occupancy rules restrict children from sharing with a single adult.");
			return(false);
		}else if(document.forms[elementID].optout.checked==true){
			if(document.forms[elementID].semail.value.length==0 && echeck(document.forms[elementID].semail.value)==false){
				alert("Please provide your email address to continue your availability search.");
				return(false);
			}
		}
	}

	if(elementID==="ao"){
		if(document.forms[elementID].destination.selectedIndex == 0){
			alert("Please select a destination");
			return(false);
		}else if(document.forms[elementID].depDay.options[document.forms[elementID].depDay.selectedIndex].value <= "12" && month <= "03" && year <= "2010") {
			alert("Please select a date in the future");
			return(false);
		}else if(document.forms[elementID].r1ad.value == 1 & document.forms[elementID].r1ch.value > 0){
			alert("Room 1: Occupancy rules restrict children from sharing with a single adult.");
			return(false);
		}else if(document.forms[elementID].r2ad.value == 1 & document.forms[elementID].r2ch.value > 0){
			alert("Room 2: Occupancy rules restrict children from sharing with a single adult.");
			return(false);
		}else if(document.forms[elementID].r3ad.value == 1 & document.forms[elementID].r3ch.value > 0){
			alert("Room 3: Occupancy rules restrict children from sharing with a single adult.");
			return(false);
		}else if(document.forms[elementID].optout.checked==true){
			if(document.forms[elementID].semail.value.length==0 && echeck(document.forms[elementID].semail.value)==false){
				alert("Please provide your email address to continue your availability search.");
				return(false);
			}
		}
	}

}