function showErrorMessage(field,name,alerttxt) {
	//alert("field:" + field + ", name:" + name + ", alerttxt :" + alerttxt);
	with (field){				
		$('.error').each( function() {
    		var element = this;
    		
			if ($(element).attr("class").indexOf(name) != -1) {
					$(element).show().addClass("show");
					$(element).text(alerttxt);
			}
		});
	}
}


function nonZeroValue_check( field,name,alerttxt ) {
	
	if ( isNaN(field.val()) ){
		showErrorMessage(field,name,alerttxt);
		return false;
	} else if ( field.val() <= 0 ) {		
			showErrorMessage(field,name,alerttxt);
			return false;
	} else {
		return true;	
	}
	
	
}

function nonNegativeValue_check( field,name,alerttxt ) {
	
	if ( isNaN(field.val()) ){
		showErrorMessage(field,name,alerttxt);
		return false;
	} else if ( field.val() < 0 ) {		
			showErrorMessage(field,name,alerttxt);
			return false;
	} else {
		return true;	
	}
	
	
}

function tooLargeValue_check( field,name,alerttxt ) {
	if ( field.val() >= 100000 ) {		
		showErrorMessage(field,name,alerttxt);
		return false;
	} else {
		return true;	
	}
	
	
}

//Removes spaces from a given string 	
function removeSpace(elem) {
	return elem.split(' ').join('');
}	


// Valid postcode only has 4-12 characters and contains :
//[a-z], [A-Z], [0-9],[space] 	 
function isPostcode(elem, country_code){		
	var isPostcodeValid = true;
		
	var isValid = postcode_is_valid(removeSpace(elem), country_code);
	
	if (isValid) {
		return true;
	} else {
		
		var answer = confirm("The '" + elem + "' postcode might be wrong. Would you like to proceed? ");
        if(answer == true){
     	   return true;
        }
        else{	         	   	
     	   return false;
        }
     }

	return isPostcodeValid;
}