function _validate_mail(str) {
   return (str.indexOf(".") > 2) && (str.indexOf("@") > 0 && (str.length) > 8);
}


function validate_mail(str) 
{
	var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	
	if (!filter.test(str)) 
	{
		return false;
	} else {
		return true;	
	}
}

function IsNumeric(strString)
{
   var strValidChars = "0123456789.";
   var strChar;
   var blnResult = true;

   if (strString.length == 0) return false;

   //  test strString consists of valid characters listed above
   for (i = 0; i < strString.length && blnResult == true; i++)
   {
      strChar = strString.charAt(i);
      if (strValidChars.indexOf(strChar) == -1)
	  {
         blnResult = false;
      }
   }
   return blnResult;
}


function isAlfaNumeric(str)
{
	rs = /^[a-zA-Z\s]+$/;
	return rs.test(str);
}

// validate date values
////////////////////////////////////////////////

var dtCh= "/";
var minYear=00;
var maxYear=09;

function isInteger(s){
	var i;
    for (i = 0; i < s.length; i++){   
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    return true;
}

function stripCharsInBag(s, bag){
	var i;
    var returnString = "";
    for (i = 0; i < s.length; i++){   
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }
    return returnString;
}

function daysInFebruary (year){
    return (((year % 4 == 0) && ( (!(year % 100 == 0)) || (year % 400 == 0))) ? 29 : 28 );
}
function DaysArray(n) {
	for (var i = 1; i <= n; i++) {
		this[i] = 31
		if (i==4 || i==6 || i==9 || i==11) {this[i] = 30}
		if (i==2) {this[i] = 29}
   } 
   return this
}

function isDate(dtStr){
	var daysInMonth = DaysArray(12)
	var pos1=dtStr.indexOf(dtCh)
	var pos2=dtStr.indexOf(dtCh,pos1+1)
	var strDay=dtStr.substring(0,pos1)
	var strMonth=dtStr.substring(pos1+1,pos2)
	var strYear=dtStr.substring(pos2+1)
	strYr=strYear
	if (strDay.charAt(0)=="0" && strDay.length>1) strDay=strDay.substring(1)
	if (strMonth.charAt(0)=="0" && strMonth.length>1) strMonth=strMonth.substring(1)
	for (var i = 1; i <= 3; i++) {
		if (strYr.charAt(0)=="0" && strYr.length>1) strYr=strYr.substring(1)
	}
	month=parseInt(strMonth)
	day=parseInt(strDay)
	year=parseInt(strYr)
	if (pos1==-1 || pos2==-1){
		alert("The date format should be : dd/mm/yy")
		return false
	}
	if (strMonth.length<1 || month<1 || month>12){
		alert("Please enter a valid month")
		return false
	}
	if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month]){
		alert("Please enter a valid day")
		return false
	}
	if (strYear.length != 2 || year==0 || year<minYear || year>maxYear){
		alert("Please enter a valid 2 digit year between 0"+minYear+" and 0"+maxYear)
		return false
	}
	if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false){
		alert("Please enter a valid date")
		return false
	}
	return true
}

function trim(stringToTrim) {
	return stringToTrim.replace(/^\s+|\s+$/g,"");
}


function validateDate(str)
{
	if ( str.length == 0 )
	{
		alert("Error! Please enter date(s) of treatment...");
		return false;
	}
	
	datesArr = str.split(",");
	
	isOK = true;
	
	for (var i=0; i<datesArr.length; i++)
	{
		datesArr[i] = trim(datesArr[i]);
		if ( !isDate( datesArr[i] ) )
		{
			return false;	
		}
	}
	
	return isOK;
	
}


function check_form(frmObj)
{
	if (frmObj.title.value.length < 2 || frmObj.title.value == " " ){
		alert("Error! Please enter your title...");
		frmObj.title.focus();
		return false;
	} else if (frmObj.forename.value.length < 2){
		alert("Error! Please enter your forename...");
		frmObj.forename.focus();
		return false;
	} else if (frmObj.surname.value.length < 2){
		alert("Error! Please enter your surname...");
		frmObj.surname.focus();
		return false;
	} else if (frmObj.houseno.value == "" || frmObj.houseno.value == " "){
		alert("Error! Please enter house no. or name...");
		frmObj.houseno.focus();
		return false;
	} else if (frmObj.street.value.length < 2 || frmObj.street.value == "  "){
		alert("Error! Please enter the street...");
		frmObj.street.focus();
		return false;
	} else if (frmObj.area.value.length < 2){
		alert("Error! Please enter the area...");
		frmObj.area.focus();
		return false;
	} else if (frmObj.town.value.length < 2){
		alert("Error! Please enter the town...");
		frmObj.town.focus();
		return false;
	} else if (frmObj.postcode.value.length < 4){
		alert("Error! Please enter the postcode...");
		frmObj.postcode.focus();
		return false;
	} else if (!validate_mail(frmObj.email.value)){
		alert("Error! Please enter a valid email address...");
		frmObj.email.focus();
		return false;
	} else if (frmObj.phone.value.length < 10){
		alert("Error! Please enter your phone number...");
		frmObj.phone.focus();
		return false;
	
	} else if ( !frmObj.treatment0.checked && !frmObj.treatment1.checked && !frmObj.treatment2.checked && !frmObj.treatment3.checked && frmObj.Therapy.value.length < 3 ){
		alert("Error! Please enter the type of treatment...");
		frmObj.Therapy.focus();
		return false;
		
	} else if ( !isAlfaNumeric( frmObj.therapist.value ) || frmObj.therapist.value.length < 2 ){
		alert("Error! Please enter the name of therapist...");
		frmObj.therapist.focus();
		return false;
	} else if (frmObj.clinic.value == ""){
		alert("Error! Please select the clinic...");
		frmObj.clinic.focus();
		return false;
	} else if (frmObj.invoice.value.length < 1  ){
		alert("Error! Please enter invoice/receipt number...");
		frmObj.invoice.focus();
		return false;
	} else if ( !IsNumeric(frmObj.amount.value) ){
		alert("Error! Please enter total amount...");
		frmObj.amount.focus();
		return false;
	} else {
		return true;
	}
}