function checkConference(chkForm,lang_e) {
		var z = 0;
		var rtnBool = false;
		for(z=0; z<chkForm.length;z++){
      		if(chkForm[z].type == 'checkbox'){
	 			if (chkForm[z].checked && chkForm[z].disabled==false) {
	 				rtnBool = true;
	 			}
	 		}
	  	}
	 	if (rtnBool==false) {
	 		if (lang_e=="en") {
	 			alert("Please select at least one conference");
	 		} else {
	 			alert("請選擇最少一個會議");
	 		}
	 	} else {
	 		document.getElementById("p_code").disabled=false;
	 	}
		return rtnBool;
	}
	
	function en_others(chkBox, txtBox) {
		if (document.getElementById(chkBox).checked==true) {
			document.getElementById(txtBox).disabled=false;
			document.getElementById(txtBox).focus();
		} else {
			document.getElementById(txtBox).disabled=true;
			document.getElementById(txtBox).value="";
		}
	}
	
	function en_region(boolean_en) {
		document.getElementById('q3_01').disabled=boolean_en;
		document.getElementById('q3_02').disabled=boolean_en;
		document.getElementById('q3_03').disabled=boolean_en;
		document.getElementById('q3_04').disabled=boolean_en;
		document.getElementById('q3_05').disabled=boolean_en;
		document.getElementById('q3_06').disabled=boolean_en;
		document.getElementById('q3_07').disabled=boolean_en;
		document.getElementById('q3_08').disabled=boolean_en;
		document.getElementById('q3_09').disabled=boolean_en;
		document.getElementById('q3_10').disabled=boolean_en;
		document.getElementById('q3_11').disabled=boolean_en;
		document.getElementById('q3_12').disabled=boolean_en;
		if (boolean_en==true) {
			document.getElementById('q3_01').checked=false
			document.getElementById('q3_02').checked=false
			document.getElementById('q3_03').checked=false
			document.getElementById('q3_04').checked=false
			document.getElementById('q3_05').checked=false
			document.getElementById('q3_06').checked=false
			document.getElementById('q3_07').checked=false
			document.getElementById('q3_08').checked=false
			document.getElementById('q3_09').checked=false
			document.getElementById('q3_10').checked=false
			document.getElementById('q3_11').checked=false
			document.getElementById('q3_12').checked=false
		}
	}
	function chkBoxCheck(chkBox) {
		if (chkBox=="T100" && document.getElementById(chkBox).checked==true) {
			if (document.getElementById("T200").disabled==false) {
				if (document.getElementById("T200").checked==true) {
					document.getElementById("T200").checked=false;
				}
			} else {
				document.getElementById("T100").checked=false;
			}
			
		}
		if (chkBox=="T200" && document.getElementById(chkBox).checked==true) {
			if (document.getElementById("T100").disabled==false) {
				if (document.getElementById("T100").checked==true) {
					document.getElementById("T100").checked=false;
				}
			} else {
				document.getElementById("T200").checked=false;
			}
		}
		if (chkBox=="T300" && document.getElementById(chkBox).checked==true) {
			if (document.getElementById("T400").disabled==false) {
				if (document.getElementById("T400").checked==true) {
					document.getElementById("T400").checked=false;
				}
			} else {
				document.getElementById("T300").checked=false;
			}
		}
		if (chkBox=="T400" && document.getElementById(chkBox).checked==true) {
			if (document.getElementById("T300").disabled==false) {
				if (document.getElementById("T300").checked==true) {
					document.getElementById("T300").checked=false;
				}
			} else {
				document.getElementById("T400").checked=false;
			}
		}
	}

	function getPromoCode(lang_e) {
		var p_id;
		p_id = document.getElementById("p_code").value;
		if (p_id!="") {
			var url;
			url = "getPromoCode.php?p_id="+p_id;
			var xmlHttp;
			try {
				// Firefox, Opera 8.0+, Safari
				xmlHttp=new XMLHttpRequest();
			} catch (e) {
				// Internet Explorer
				try {
					xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
				} catch (e) {
					try {
						xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
					}
					catch (e) {
						alert("Your browser does not support AJAX!");
						return false;
					}
				}
			}
			xmlHttp.onreadystatechange=function() {
				if(xmlHttp.readyState==4) {
					var strResult = xmlHttp.responseText;
					if (strResult!="") {
						if (strResult=="N") {
							if (lang_e=="en") {
								alert("No quota left for the code you entered.");
							} else {
								alert("閣下的參展商折扣碼已無效");
							}
							document.getElementById("p_code").value="";
							document.getElementById("p_discount").value="0";
						} else {
							if (lang_e=="en") {
								alert("You will enjoy special discount.");
							} else {
								alert("閣下可享有參展商特別折扣");
							}
							document.getElementById("p_code").disabled=true;
							document.getElementById("getprice").disabled=true;
							document.getElementById("p_discount").value=strResult;
						}
					} else {
						if (lang_e=="en") {
							alert("Invalid exhibitor rate promotional code!");
						} else {
							alert("錯誤參展商折扣碼，請輸入正確折扣碼");
						}				
						document.getElementById("p_code").value="";
						document.getElementById("p_discount").value="0";
					}
				}
			}
			xmlHttp.open("GET",url,true);
			xmlHttp.send(null);
		} else {
			if (lang_e=="en") {
				alert("Please type the exhibitor rate promotional code.");
			} else {
				alert("請輸入參展商折扣碼");
			}
		}
	}