Uncaught TypeError: Object [object Object] has no method 'multipleSelect'

Uncaught TypeError: Object [object Object] has no method 'multipleSelect'

I have used the ajax function when calling this function with
multipleSelect like this. suppose that I have a function that called again
in ajax load page
I have included jquery and jquery.multiselect.js include file also
$('#demo3').multipleSelect({
placeholder: "Select Country",
filter:true
});
});
$("#button").click(function(){
$.ajax({
url:"http:localhost/mydata",
success:function(data){
$('#demo4').multiSelect({
placeholder: "Select Country",
filter:true
});
},
});
});
demo3 has successfully generate multiselect function. But when I have
pressed button the code in demo4 has error that multiselect function has
not been registered in a page?
The error code said.. Uncaught TypeError: Object [object Object] has no
method 'multipleSelect'
How I can solve this ? Thanks