onMouseOut
The instruction(s) to be executed are placed within quotes. This event handler will execute the instruction(s) when the mouse pointer passes over and away from the object to which it has been assigned.

The following example will swap 'image1.jpg' with 'image2.jpg' when the mouse hits the 'image1.jpg' graphic. After the mouse moves away from the 'image2.jpg' graphic now displayed, it will changed back to the original 'image1.jpg' graphic:
<A HREF="https://www.WalkTheGeek.com" onMouseOver="swap.src=image2.jpg" onMouseOut="swap.src=image1.jpg"><IMG SRC="image1.jpg" NAME="swap">WalkTheGeek</A>
This Event Handler is used with the following:

A
ACRONYM
ADDRESS
APPLET
AREA
B
BIG
BLOCKQUOTE
BODY
BUTTON
CAPTION
CENTER
CITE
CODE
DD
DEL
DFN
DIR
DIV
DL
DT
EM
FIELDSET
FONT
FORM
H1
H2
H3
H4
H5
H6
HR
I
IMG
INS
KBD
LABEL
LEGEND
LI
LISTING
MAP
MARQUEE
MENU
OL
P
PLAINTEXT
PRE
Q
S
SAMP
SELECT
SMALL
SPAN
STRIKE
STRONG
SUB
SUP
TABLE
TBODY
TD
TEXTAREA
TFOOT
THEAD
TR
TT
U
UL
VAR
XMP