function numbersonly(myfield, e, dec) {
var key;
var keychar;

if (window.event)
   key = window.event.keyCode;
else if (e)
   key = e.which;
else
   return true;
keychar = String.fromCharCode(key);

// control keys
if ((key==null) || (key==0) || (key==8) || (key==9) || (key==13) || (key==27) )
   return true;

// numbers
else if ((("+0123456789").indexOf(keychar) > -1))
   return true;

// decimal point jump
else 
	if (dec && (keychar == ".")) {
	   myfield.form.elements[dec].focus();
	   return false;
	} 
else
   return false;
}


function OveritFormular(theField) {
	if ((theField.jmeno.value == '') || (theField.firma.value == '') || (theField.email.value == '') || (theField.zprava.value == '')) {
		alert('Před odesláním je nutné vyplnit jméno, příjmení, email a dotaz!')
		if (theField.zprava.value == '')
			theField.zprava.focus()
		if (theField.email.value == '')
			theField.email.focus()
		if (theField.firma.value == '')
			theField.firma.focus()
		if (theField.jmeno.value == '')
			theField.jmeno.focus()
		return false
	}  else {
		if (!zkontrolujEmail(theField.email))
			return false
		else
			return true
	}  
}

function zkontrolujEmail(poleemail) {
if (window.RegExp) { 
	var re = new RegExp('^[_a-zA-Z0-9\.\-]+@[_a-zA-Z0-9\.\-]+\.[a-zA-Z]{2,4}$');
	//var re = new RegExp('^[a-zA-Z0-9]+([_\.\-][a-zA-Z0-9]+)?@([a-zA-Z0-9\-]+\.)+[a-zA-Z0-9]{2,6}$');
	if (!re.test(poleemail.value))	{
		window.alert("Emailová adresa nemá správný formát!");
		return false;
		}
	}
return true;
}