function empty_field(field) {

	if (document.getElementById(field).value == "enter text...") {
	
		document.getElementById(field).value = "";
		
	}
	
}

function empty_field_blur(field) {

	if (document.getElementById(field).value == "" || document.getElementById(field).value == "enter text...") {
	
		document.getElementById(field).value = "enter text...";
		
	}
	
}


function check_form() {

	input = document.getElementById('name');
	
	if (input.value.length < 1 || input.value == "enter text...") {
	
		alert('Please enter your name!');
		input.value = "";
		input.focus();
		return false;
		
	}
	
	input = document.getElementById('contact_email');
	
	if (input.value.length > 1 && input.value != "enter text...") {
	
		if (!checkMail(input.value)) {
			
			alert('The e-mail adres is not valid!');
			input.focus();
			return false;
		
		}
		
	}
	else {
	
		alert('Please enter your e-mail adress!');
		input.value = "";
		input.focus();
		return false;
		
	}
	
	input = document.getElementById('telephone');
	
	if (input.value.length < 1 || input.value == "enter text...") {
	
		alert('Please enter your telehpone number!');
		input.value = "";
		input.focus();
		return false;
		
	}
	
	input = document.getElementById('question');
	
	if (input.value.length < 1 || input.value == "enter text...") {
	
		alert('Please enter your question!');
		input.value = "";
		input.focus();
		return false;
		
	}
	
	
	return true;
	
}