window.addEventListener
? /* standard */ window.addEventListener ("load", nav_init, false)
: /* IE */ window.attachEvent ("onload", nav_init);

var trans = new Image (200, 200);
trans.src = "/img/transparent.png";

m_it = new Array (6);
m_it[0] = "kp";
m_it[1] = "ls";
m_it[2] = "pj";
m_it[3] = "pf";
m_it[4] = "kt";
m_it[5] = "tp";

var m_it_hover = 0;
var m_anim_dst = null;

var m_u_frames = new Array (6);
var m_u_current = 0;
var m_anim_speed = 0;
var m_anim_timeout_state = null;

function nav_init () {
// 	if (!document.getElementById || !document.createElement) {
// 		return;
// 	}

	for (var i = 0; i < 6; i++) {
	    if (!document.images[m_it[i]]) {
	    	continue;
	    }
		document.images[m_it[i]].addEventListener
		? document.images[m_it[i]].addEventListener ("mouseover", animate_u, false)
		: document.images[m_it[i]].attachEvent ("onmouseover", animate_u);
		document.images[m_it[i]].addEventListener
		? document.images[m_it[i]].addEventListener ("mouseout", hide_u, false)
		: document.images[m_it[i]].attachEvent ("onmouseout", hide_u);
	}
	
}

function loadAnimFrames (i) {
	if (m_u_frames[i] == null) {
		m_u_frames[i] = new Array (5);
	}
	for (var j = 0; j < 5; j++) {
		m_u_frames[i][j] = new Image();
		m_u_frames[i][j].src = "/img/i_u/"+m_it[i]+"_"+(j+1)+".png";
	}
}

function imageIndex (img) {
        var imgId;
        if (!img) {
                return -1;
        }
        if (img.name) {
                imgId = img.name;
        } else if (img.id) {
                imgId = img.id;
        } else {
                return -1;
        }
        for (var i = 0; i < 6; i++) {
                if (imgId == m_it[i]) {
                        return i;
                }
        }
        return -1;
}

function animate_u (evt) {
        var evtTarget;
        if (!evt) {
                evt = window.event;
        }
        if (evt.target) {
                evtTarget = evt.target;
        } else if (evt.srcElement) /*IE*/ {
                evtTarget = evt.srcElement;
        }
        i = imageIndex (evtTarget);
        if (i < 0) {
                return;
        }
        if (m_u_frames[i] == null) {
                loadAnimFrames (i);
        }
        if (m_anim_dst != null) {
                stopAnimation();
        }
        m_anim_dst = document.images["u_"+m_it[i]];
        m_it_hover = i;
        animator();
}

function hide_u (evt) {
        var evtTarget;
        if (!evt) {
                evt = window.event;
        }
        if (evt.target) {
                evtTarget = evt.target;
        } else if (evt.srcElement) /*IE*/ {
                evtTarget = evt.srcElement;
        }
        i = imageIndex (evtTarget);
        if (i >= 0) {
                document.images["u_"+m_it[i]].src = trans.src;
        }
}

function animator() {
	if (m_u_current < 5) {
		if (m_u_current > 0
		    && m_anim_dst != null
		    && m_anim_dst.src == trans.src) {
			stopAnimation();
			return;
		}
		m_anim_dst.src = m_u_frames[m_it_hover][m_u_current].src;
		m_u_current = (m_u_current + 1);
		if (m_anim_speed == 0) {
			m_anim_speed = 40;
		} else {
			m_anim_speed = (m_anim_speed + 20);
		}
		m_anim_timeout_state = setTimeout ("animator()", m_anim_speed);
	} else {
		stopAnimation();
	}
}

function stopAnimation (clear) {
	m_it_hover = 0;
	m_u_current = 0;
	m_anim_speed = 0;
	if (m_anim_timeout_state != null) {
		clearTimeout (m_anim_timeout_state);
		m_anim_timeout_state = null;
	}
	m_anim_dst = null;
}