function numCheck(field,allow) {
// this one is used onkeyup and check if field is number and makes it red if not
	var check = true;
	allow += "1234567890";
	var value = field.value; //get characters
 	//check that all characters are digits, ., -, or ""
	for(var i=0;i < field.value.length; ++i) {
		var new_key = value.charAt(i); //cycle through characters
		if((allow.indexOf(new_key) == -1) && !(new_key == "")) {
			check = false;
			break;
		}
	}
	//apply appropriate colour based on value
	if(!check) {
		field.style.backgroundColor = "red";
	} else {
		field.style.backgroundColor = "white";
	}
}

function phoneCheck(x) {
	//strip out acceptable non-numeric characters
	var stripped = x.replace(/[\(\)\.\-\ ]/g, '');
	//allow leading +
	if (stripped.indexOf('+') == 0) {
		stripped = stripped.substr(1,stripped.length-1);
	}
	if (isNaN(parseInt(stripped))) {
		return false;
	}
	if (stripped.length < 11 || stripped.length > 12) {
		return false;
	}
	return true;
}

function checkEmail(formInput) {
    if (typeof(formInput) != "object") {
        alert("Validation not supported on this browser.");
        return(false);
    }
    var message;
    if (stringEmpty(formInput.value)) {
        message = "Please enter an email address; this is required by our card processor and is used to send you payment confirmation\nWe will only use it to contact you about your order unless you choose to join our news mailing list.";
        alert(message);
	    return (false);
    } else if (noAtSign( formInput.value )) {
        message = "Error! The address \"" + formInput.value + "\" does not contain an '@' character.";
        alert(message);
	    return (false);
    } else if (nothingBeforeAt(formInput.value)) {
        message = "Error! The address \"" + formInput.value;
        message += "\" must contain at least one character before the '@' character";
        alert(message);
	    return (false);
    } else if (noLeftBracket(formInput.value)) {
        message = "Error! The address \"" + formInput.value;
        message += "\" contains a right square bracket ']',\nbut no corresponding left square bracket '['.";
        alert(message);
	    return (false);
    } else if (noRightBracket(formInput.value)) {
        message = "Error! The address \"" + formInput.value;
        message += "\" contains a left square bracket '[',\nbut no corresponding right square bracket ']'.";
        alert( message);
	    return (false);
    } else if (noValidPeriod(formInput.value)) {
        message = "Error! The address \"" + formInput.value + "\" must contain a period ('.') character.";
        alert(message);
	    return (false);
    } else if (noValidSuffix(formInput.value)) {
        message = "Error! The address \"" + formInput.value;
        message += "\" must contain a two, three or four character suffix.";
        alert(message);
	    return (false);
    }
    
    return (true);
}

function checkValid (formField) {
    if ( checkValidation ( formField ) == true ) {
        //alert ( 'E-Mail Address Validates OK' );
        return true;
    }

    return ( false );
}

function stringEmpty (formField) {
    // CHECK THAT THE STRING IS NOT EMPTY
    if ( formField.length < 1 ) {
        return ( true );
    } else {
        return ( false );
    }
}

function noAtSign (formField) {
    // CHECK THAT THERE IS AN '@' CHARACTER IN THE STRING
    if (formField.indexOf ('@', 0) == -1) {
        return ( true )
    } else {
        return ( false );
    }
}

function nothingBeforeAt (formField) {
    // CHECK THERE IS AT LEAST ONE CHARACTER BEFORE THE '@' CHARACTER
    if ( formField.indexOf ( '@', 0 ) < 1 ) {
        return ( true )
    } else {
        return ( false );
    }
}

function noLeftBracket (formField) {
    // IF EMAIL ADDRESS IN FORM 'user@[255,255,255,0]', THEN CHECK FOR LEFT BRACKET
    if ( formField.indexOf ( '[', 0 ) == -1 && formField.charAt (formField.length - 1) == ']') {
        return ( true )
    } else {
        return ( false );
    }
}

function noRightBracket (formField) {
    // IF EMAIL ADDRESS IN FORM 'user@[255,255,255,0]', THEN CHECK FOR RIGHT BRACKET
    if (formField.indexOf ( '[', 0 ) > -1 && formField.charAt (formField.length - 1) != ']') {
        return ( true );
    } else {
        return ( false );
    }
}

function noValidPeriod (formField) {
    // IF EMAIL ADDRESS IN FORM 'user@[255,255,255,0]', THEN WE ARE NOT INTERESTED
    if (formField.indexOf ( '@', 0 ) > 1 && formField.charAt (formField.length - 1 ) == ']')
        return ( false );

    // CHECK THAT THERE IS AT LEAST ONE PERIOD IN THE STRING
    if (formField.indexOf ( '.', 0 ) == -1)
        return ( true );

    return ( false );
}

function noValidSuffix(formField) {
    // IF EMAIL ADDRESS IN FORM 'user@[255,255,255,0]', THEN WE ARE NOT INTERESTED
    if (formField.indexOf('@', 0) > 1 && formField.charAt(formField.length - 1) == ']') {
        return ( false );
    }

    // CHECK THAT THERE IS A TWO OR THREE CHARACTER SUFFIX AFTER THE LAST PERIOD
    var len = formField.length;
    var pos = formField.lastIndexOf ( '.', len - 1 ) + 1;
    if ( ( len - pos ) < 2 || ( len - pos ) > 4 ) {
        return ( true );
    } else {
        return ( false );
    }
}

function stripLeadSpace(x) {
	while (x.slice(0,1) == " "){
		x = x.substr(1,x.length-1);
	}
	return x;
}

function checkPC(){ //check postcode format is valid
	e=document.getElementById("postcode");
	test = e.value;
 	test = test.toUpperCase(); //Change to uppercase
 	test = stripLeadSpace(test);
 	size = test.length; 	
 	while(test.slice(size-1,size)== " ") { //Strip trailing spaces
  		test = test.substr(0,size-1);
  		size = test.length
  	}
 	e.value = test; //write back to form field
//	return false;
 	if ((size < 6) || (size > 8)){ //Code length rule
     alert(test + " is not a valid postcode - wrong length");
    //  e.focus();
  		return false;
  	}
 	if (!(isNaN(test.charAt(0)))) { //leftmost character must be alpha character rule
   alert(test + " is not a valid postcode - cannot start with a number");
//   e.focus();
   		return false;
  	}
 	if (isNaN(test.charAt(size-3))) { //first character of inward code must be numeric rule
   alert(test + " is not a valid postcode - alpha character in wrong position");
//   e.focus();
   		return false;
  	}
 	if (!(isNaN(test.charAt(size-2)))){ //second character of inward code must be alpha rule
   alert(test + " is not a valid postcode - number in wrong position");
//   e.focus();
   		return false;
  	}
 	if (!(isNaN(test.charAt(size-1)))) { //third character of inward code must be alpha rule
   alert(test + " is not a valid postcode - number in wrong position");
//   e.focus();
   		return false;
  	}
 	if (!(test.charAt(size-4) == " ")) {//space in position length-3 rule
   alert(test + " is not a valid postcode - no space or space in wrong position");
//   e.focus();
   		return false;
   	}
 	count1 = test.indexOf(" ");
	count2 = test.lastIndexOf(" ");
 	if (count1 != count2) {//only one space rule
   alert(test + " is not a valid postcode - only one space allowed");
//   e.focus();
   		return false;
  	}
//alert("Postcode Format OK");
	return true;
}