function imageOn() 
{	
    this.src = this.src.replace( ".gif", "_on.gif" );
}

function imageOff() 
{
    this.src = this.src.replace( "_on.gif", ".gif" );
}

function attachEventHandlers()
{        
    var employerbtn = document.getElementById( "employerbtn" );
    if ( employerbtn )
    {
		addEvent( employerbtn, "mouseover", imageOn );
		addEvent( employerbtn, "mouseout", imageOff );
    }
    
    var learnerbtn = document.getElementById( "learnerbtn" );
    if ( learnerbtn )
    {
		addEvent( learnerbtn, "mouseover", imageOn );
		addEvent( learnerbtn, "mouseout", imageOff );
    }
    
    var providerbtn = document.getElementById( "providerbtn" );
    if ( providerbtn )
    {
		addEvent( providerbtn, "mouseover", imageOn );
		addEvent( providerbtn, "mouseout", imageOff );
    } 
    
    var backbtn = document.getElementById( "backbtn" );
    if ( backbtn )
    {
		addEvent( backbtn, "mouseover", imageOn );
		addEvent( backbtn, "mouseout", imageOff );
    } 
            
    var projectsbtn = document.getElementById( "projectsbtn" );
    if ( projectsbtn )
    {
		addEvent( projectsbtn, "mouseover", imageOn );
		addEvent( projectsbtn, "mouseout", imageOff );
    }  
    
    var newsarchivebtn = document.getElementById( "newsarchivebtn" );
    if ( newsarchivebtn )
    {
		addEvent( newsarchivebtn, "mouseover", imageOn );
		addEvent( newsarchivebtn, "mouseout", imageOff );
    }
    
    var leftarrowbtn = document.getElementById( "leftarrowbtn" );
    if ( leftarrowbtn )
    {
		addEvent( leftarrowbtn, "mouseover", imageOn );
		addEvent( leftarrowbtn, "mouseout", imageOff );
    } 
    
    var rightarrowbtn = document.getElementById( "rightarrowbtn" );
    if ( rightarrowbtn )
    {
		addEvent( rightarrowbtn, "mouseover", imageOn );
		addEvent( rightarrowbtn, "mouseout", imageOff );
    }
    
    var memberinstitutionsbtn = document.getElementById( "memberinstitutionsbtn" );
    if ( memberinstitutionsbtn )
    {
		addEvent( memberinstitutionsbtn, "mouseover", imageOn );
		addEvent( memberinstitutionsbtn, "mouseout", imageOff );
    } 
    
    var idahologobtn = document.getElementById( "idahologobtn" );
    if ( idahologobtn )
    {
		addEvent( idahologobtn, "mouseover", imageOn );
		addEvent( idahologobtn, "mouseout", imageOff );
    }
    
    var viewprojectsbtn = document.getElementById( "viewprojectsbtn" );
    if ( viewprojectsbtn )
    {
		addEvent( viewprojectsbtn, "mouseover", imageOn );
		addEvent( viewprojectsbtn, "mouseout", imageOff );
    }         
}

function addEvent( obj, type, fn )
{
	if ( obj )
	{
		if ( obj.addEventListener )
		{
			obj.addEventListener( type, fn, false );
		}
		else if ( obj.attachEvent )
		{
			obj[ "e" + type + fn ] = fn;
			obj[ type + fn ] = function() { obj[ "e" + type + fn ]( window.event ); }
			obj.attachEvent( "on" + type, obj[ type + fn ] );
		}
	}
}

function removeEvent( obj, type, fn )
{
	if ( obj.removeEventListener )
	{
		obj.removeEventListener( type, fn, false );
	}
	else if ( obj.detachEvent )
	{
		obj.detachEvent( "on" + type, obj[ type + fn ] );
		obj[ type + fn ] = null;
		obj[ "e" + type + fn ] = null;
	}
}

// Load in all the event on body load
addEvent( window, "load", attachEventHandlers );