function Validovat(theForm) {
       var email = new RegExp("^[^.]+(\.[^.]+)*@([^.]+[.])+[a-z]{2,4}$");
       if (document.getElementById('email').value=="" || !email.test(document.getElementById('email').value))
       {
         alert("Zadejte, prosím, svůj email.");
         document.getElementById('email').focus();
         return false;
       }

       if ((document.getElementById('phone').value=="")||(document.getElementById('phone').value.length < 9))
       {
         alert("Zadejte, prosím, svůj telefon.");
         document.getElementById('phone').focus();
         return false;
       }

     return true;
}

function SelectProduct( ID ) {
	switch( ID ) {
		case 'popis':
			document.getElementById('stazeniSel').className='normal';
			document.getElementById('imagesSel').className='normal';
			document.getElementById('stazeni').style.display='none';
			document.getElementById('images').style.display='none';
			break;
		case 'stazeni':
			document.getElementById('popisSel').className='normal';
			document.getElementById('imagesSel').className='normal';
			document.getElementById('popis').style.display='none';
			document.getElementById('images').style.display='none';
			break;
		case 'images':
			document.getElementById('popisSel').className='normal';
			document.getElementById('stazeniSel').className='normal';
			document.getElementById('popis').style.display='none';
			document.getElementById('stazeni').style.display='none';
			break;
	}
	document.getElementById( ID + 'Sel' ).className='selected';
	document.getElementById( ID ).style.display='block';
	return false;
}