var browser = navigator.appName;
var version = navigator.appVersion
var count = 50;

function start() {
    if ( browser == "Microsoft Internet Explorer" )
        document.getElementById('content2').style.height = document.documentElement.clientHeight + "px";
    if ( browser == "Microsoft Internet Explorer" && parseFloat(version.split("MSIE")[1]) < 7 ) {
        document.getElementById('content').style.display = "none";
        document.getElementById('content2').style.display = "block";
    }
    else
        content();
    setInterval('check()', 500);
}

function content() {
    count--;
    if ( count > 0 ) {
        if ( browser == "Microsoft Internet Explorer" )
            document.getElementById('content').style.filter = "alpha(opacity=" + (count * 50) + ")";
        else
            document.getElementById('content').style.opacity = count / 50;
        setTimeout("content()", 12);
    }
    else {
        if ( browser == "Microsoft Internet Explorer" )
            document.getElementById('content').style.filter = "alpha(opacity=0)";
        else
            document.getElementById('content').style.opacity = 0;
        document.getElementById('content').style.display = "none";
        document.getElementById('content2').style.display = "block";
        count = 1;
        content2();
    }
}

function content2() {
    if (count <= 40 ) {
        if ( browser == "Microsoft Internet Explorer" )
            document.getElementById('content2').style.filter = "alpha(opacity=" + (count * 40) + ")";
        else
            document.getElementById('content2').style.opacity = count / 40;
        count++;
        setTimeout("content2()", 10);
    }
}

function check() {
    if ( document.forms['offer'].elements['name'].value != "" && document.forms['offer'].elements['mail'].value != "" && document.forms['offer'].elements['price'].value != "" ) {
        var reg = /^[a-zA-Z0-9_-]+(\.[a-zA-Z0-9_-]+)*@([a-zA-Z0-9_-]+)(\.[a-zA-Z0-9_-]+)*(\.[a-zA-Z]{2,4})$/i;
        if ( document.forms['offer'].elements['mail'].value.match(reg) == null )
            document.getElementById('submit').setAttribute('disabled', 'disabled');
        else
            setTimeout("document.getElementById('submit').removeAttribute('disabled')", 1500);
    }
    else
        document.getElementById('submit').setAttribute('disabled', 'disabled');
}