var ksub = 1;
var ssub = 1;
function checkEnter() {
    if ( window.event && window.event.keyCode == 13 ) { 
        if ( ksub ) { ksub = 0; } else { return false; } 
    } 
    return true;
}

function submitOnce() {
    if ( ssub ) {
        setTimeout( 'ssub = 1', 1000 );
        ssub = 0;
        return true;
    }
    return false;	
}

function jump_to(sel) {
    var i = sel.selectedIndex;
    if (i >= 0 && sel.options[i].value != '')
        location.href = sel.options[i].value;
}

function jump_to_by_id(id) {
    var sel = document.getElementById(id);
    if (sel) {
        var i = sel.selectedIndex;
        if (i >= 0 && sel.options[i].value != '')
            location.href = sel.options[i].value;
    }
}