var aID = new Array();
aID[0]="home_button";
aID[1]="about_button";
aID[2]="portfolio_button";
aID[3]="faq_button";
aID[4]="contact_button";
aID[5]="change_theme_button";

var nInterval=1;
var nIncrement=2;
var nStartPos=-80;
var nEndPos=-60;
var nStartPosChangeTheme=-45;
var nEndPosChangeTheme=-25;
var aCurrentPos = new Array();
var aTimerOut = new Array();
var aTimerBack = new Array();

function GetItemNo(strItem)
{
    var nItem=0;
    for(var i=0;i<aID.length;i++)
    {
        if(aID[i]==strItem)
        {
            nItem = i;
            break;
        }
    }
    return nItem;
}

function onMouseOverMenu()
{	
    //Get the correct button...
    var strItem = this.id;
    
    if(document.getElementById(strItem)!=null)
    {   
        var nItemNo = GetItemNo(strItem);
        clearTimeout(aTimerBack[nItemNo]);
        aTimerOut[nItemNo] = setTimeout("selectItem('"+strItem+"',"+nItemNo+")",nInterval);
    }
}


function selectItem(strItem,nItemNo)
{   
    var nThisEndPos = nEndPos;
    if(aID[nItemNo]=="change_theme_button")
    {
        nThisEndPos = nEndPosChangeTheme;
    }
    
    if(aCurrentPos[nItemNo]>=nThisEndPos) 
    {   
        clearTimeout(aTimerOut[nItemNo]);
    }
    else
    {
        aCurrentPos[nItemNo] += nIncrement;
        if(aID[nItemNo]=="change_theme_button")
        {
            document.getElementById(strItem).style.right=aCurrentPos[nItemNo]+"px";
        }
        else
        {
            document.getElementById(strItem).style.left=aCurrentPos[nItemNo]+"px";
        }
        aTimerOut[nItemNo] = setTimeout("selectItem('"+strItem+"',"+nItemNo+")",nInterval);
    }
}


function onMouseOutMenu()
{	
    //Get the correct button...
    var strItem = this.id;
    
    //Set opacity...
    if(document.getElementById(strItem)!=null)
    {
        var nItemNo = GetItemNo(strItem);
        clearTimeout(aTimerOut[nItemNo]);
        aTimerBack[nItemNo] = setTimeout("deselectItem('"+strItem+"',"+nItemNo+")",nInterval);
    }
}

function deselectItem(strItem,nItemNo)
{   
    var nThisStartPos = nStartPos;
    if(aID[nItemNo]=="change_theme_button")
    {
        nThisStartPos = nStartPosChangeTheme;
    }
    
    if(aCurrentPos[nItemNo]<=nThisStartPos) 
    {  
        clearTimeout(aTimerBack[nItemNo]);
    }
    else
    {
        aCurrentPos[GetItemNo(strItem)] -= nIncrement;
        if(aID[nItemNo]=="change_theme_button")
        {
            document.getElementById(strItem).style.right=aCurrentPos[nItemNo]+"px";
        }
        else   
        {
            document.getElementById(strItem).style.left=aCurrentPos[nItemNo]+"px";
        }
            
        aTimerBack[nItemNo] = setTimeout("deselectItem('"+strItem+"',"+nItemNo+")",nInterval);
    }
}

function onLoadBody()
{   
    //assign mouse events to all ids
    for(var i=0;i<aID.length;i++)
    {
        if(document.getElementById(aID[i])!=null)
        {
            //Set handlers...
            document.getElementById(aID[i]).onmouseover = onMouseOverMenu;
            document.getElementById(aID[i]).onmouseout = onMouseOutMenu;
            
            //Set start positions and initialise arrays...
            if(aID[i]=="change_theme_button")
            {   
                document.getElementById(aID[i]).style.right=nStartPosChangeTheme+"px"; 
                aCurrentPos[i]=nStartPosChangeTheme;
            }
            else
            {
                document.getElementById(aID[i]).style.left=nStartPos+"px"; 
                aCurrentPos[i]=nStartPos;
            }
            
            aTimerOut[i]=0;
            aTimerBack[i]=0;
            
        }
    }
    
}