function zkontrolujemail( obj )
{

    if( document.getElementById(obj) )
    {

        if (window.RegExp){

            var email = document.getElementById(obj);

        		var znaky = new RegExp("^[^.]+(\.[^.]+)*@([^.]+[.])+[a-z]{2,3}$");

        		if(!znaky.test(email.value)){
          			window.alert("Zadaná adresa není platným e-mailem!");
          			email.focus();
          			return false;
        		}
      	}
    }

}

function zobraz_vetu(Obj, Id_divu, Veta)
{

    var blok = document.getElementById(Id_divu);
    var bloka_veta = document.getElementById(Obj);

    if( blok.style.display == "none" )
    {
        blok.style.display = "block";
        bloka_veta.innerHTML = "Skrýt "+Veta;
    } else {
        blok.style.display = "none";
        bloka_veta.innerHTML = "Zobrazit "+Veta;
    }
}


function ShowClose( div, div2 )
{

    if (document.getElementById && document.getElementById(div))
    {
        var divId = document.getElementById(div);
        
        if( divId.style.display == "none" )
        {
            divId.style.display = "block";
            div2.src = "../pictures/bann_zavrit.jpg";
        } else {
            divId.style.display = "none";
            div2.src = "../pictures/bann_otevrit.jpg";
        }
        
    }

}