function createCookie(name,value,days) {
    if (days) {
        var date = new Date();
        date.setTime(date.getTime()+(days*24*60*60*1000));
        var expires = "; expires="+date.toGMTString();
    }
    else var expires = "";
    document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
    var nameEQ = name + "=";
    var ca = document.cookie.split(';');
    for(var i=0;i < ca.length;i++) {
        var c = ca[i];
        while (c.charAt(0)==' ') c = c.substring(1,c.length);
        if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
    }
    return null;
}

function eraseCookie(name) {
    createCookie(name,"",-1);
}



var selMnu = null
var selSubMnu = null
var activeMnu = null //main menu item corresponding to the page being displayed

function mnuOver(id) {
    
    //collapse previous submenu
    mnuCollapse();
                
    //expand selected submenu
    selMnu = document.getElementById('nav' + id);
    selSubMnu = document.getElementById('subnav' + id);
    if (activeMnu != selMnu) {
        selMnu.className = 'nav navHover';
    } else {
        selMnu.className = 'nav navActive';
    }               
    
    if (selSubMnu) {
        selSubMnu.style.display='block';
    }
}

function mnuOut(id) {
    //collapse previous submenu
    mnuCollapse();
}

function mnuCollapse() {
    //collapse previous submenu
    if (selMnu) {
        if (activeMnu != selMnu) {
            selMnu.className = 'nav';
            selMnu = null;
        }
    }
    
    if (selSubMnu) {
        selSubMnu.style.display='none';
        selSubMnu = null;
    }                
}

function mnuSaveActive(id) {
    //save clicked main menuitem to cookie
    createCookie('mnuactive',id,0)  //0: cookie is trashed when the user closes the browser
}

function mnuSetActiveItem() {
    //hilite the selected main menu item, which was saved to a cookie
    var id = readCookie('mnuactive');
    if (id) {
        activeMnu = document.getElementById('nav' + id);
        if (activeMnu) {
            activeMnu.className = 'nav navActive';
        }    
    }
}

function clearTextbox(obj,text){
    if (obj.value == text){ 
        obj.value= "";
    }
}

function fillTextbox(obj, text){
    if (obj.value == ''){
        obj.value= text;
    }
}