jquery image change mouseover / mouseout

<img src="<?=$g4[path]?>/images/main/cus_nor.gif" class="chngimg"/>

 

<script>

$(document).ready(function(){

$(".chngimg").mouseover(function(){

var str1 = $(this).attr("src");

var str2 = str1.substring( 0,(str1).length-7);

 

str2 = str2 + "ov";

str3 = str1.substring( (str1.length-3),str1.length);

str4 = str2 + "."  + str3;

 

$(this).attr("src",str4);

});

$(".chngimg").mouseout(function(){

var str1 = $(this).attr("src");

var str2 = str1.substring( 0,(str1).length-6);

 

str2 = str2 + "nor";

str3 = str1.substring( (str1.length-3),str1.length);

str4 = str2 + "."  + str3;

 

$(this).attr("src",str4);

});

});

</script>