function SendData()
{
if(window.document.forms.form1.jmeno.value=="")	{
		alert("Please write your name !")
		window.document.forms.form1.jmeno.focus()
		return false
}
if(window.document.forms.form1.email.value=="")	{
		alert("Please write your e-mail adress !")
		window.document.forms.form1.email.focus()
		return false
}
else{
	 exp=/^[_a-zA-Z0-9\.\-]+@[_a-zA-Z0-9\.\-]+\.[a-zA-Z]{2,4}$/
	 str=window.document.forms.form1.email.value
	 if (!str.match(exp)){
	 	alert("E-mail adress is probably wrong !")
		window.document.forms.form1.email.focus()
		return false
	 }
}
if(window.document.forms.form1.telefon.value=="")	{
		alert("Please write your phone number !")
		window.document.forms.form1.telefon.focus()
		return false
}
if(window.document.forms.form1.pozadavek.value=="")	{
		alert("Message is empty !")
		window.document.forms.form1.pozadavek.focus()
		return false
}
}