You cannot change value of input type file using Js but can take seperate div bellow that and display file name in it.
if you work with ´jquery 1.8´, the selector ´type=file´ works correctly but if you work with ´jquery 1.6´ this selector will not work. the correct way is to use this type of selectors:
$('input[type="file"]')
or, you can use this type selector, with class:
HTML:
<input class="input-type-file" type="file" name="file_1" enctype="multipart/form-data" />
JS:
$('.input-type-file')