function InvokePopup(url, width, height) {
    var params = 'width=' + width + ', height=' + height;

    var left = (screen.width - width) / 2;
    var top = (screen.height - height) / 2;

    params += ', top=' + top + ', left=' + left;
    params += ', location=no';
    params += ', titlebar =yes';
    params += ', menubar=no';
    params += ', resizable=no';
    params += ', scrollbars=no';
    params += ', toolbar=no';
    params += ', status=yes';

    var newwin = window.open(url, '_blank', params);

    if (window.focus) { newwin.focus() }

    //return false;
}

/** Permite apenas dígitos em textbox (Use: onkeypress="return isNumberKey(event)" ) **/

function isNumberKey(evt) {
    var charCode = (evt.which) ? evt.which : event.keyCode

    if (charCode > 31 && (charCode < 48 || charCode > 57))
        return false;

    return true;
}