function open_dialog(x,y,url,wantfocus,dlgname)
{
 var scr = window.screen;
 var xorig = scr.availWidth / 2 - x / 2 ;
 var yorig = scr.availHeight /  2 - y / 2 ;
 var dialog = window.open(url,'dialog',"top="+yorig+",left="+xorig+",height="+y+",width="+x+",scrollbars=1,status=0,toolbar=no,menubar=0,scrollbars=0,location=0");
 if(wantfocus)
  dialog.focus();
}

function control_form(lang)
{
	if ( (document.contform.jmeno.value=='') ||
	     (document.contform.email.value=='') )
	 {
		if (lang=='CZ')
			alert('Vyplňte prosím všechny kolonky označené *');
		else
			alert('Please fill all fields marked *');
		return false;
	 } 
	 
	 var regxp = /^([a-zA-Z0-9_\.\-])+\@([a-zA-Z0-9_\.\-])+\.([a-zA-Z]){2,4}$/
	 
	 if (!regxp.test(document.contform.email.value))
	 {
	 	if (lang=='CZ')
		 	alert('E-mailová adresa není v korektním tvaru');
		else
			alert('Incoreect e-mail address');
	 	return false;
	 }
}