Populate a file input type on load.

Hello, I have created a dynamic form where the user can add several files for upload. This form is a popup to the main form. When the user clicks submit on the popup form I do not upload the files straight away but rather I save the info in a hidden variable. When the user changes his mind and goes back to the file upload popup form again I would like to display on the file input fields the values he previously selected. However for some reason it does not seem to work. The way I create the dynamic form is the following:

//create a new input object--this is the actual textbox
obj=document.createElement("input");
                        
//give it a type
obj.type="file";
                        
// give it a size
obj.size="75";
                        
//give it an id
obj.id="file"+cnt;
                        
//add the object to the form
frm.appendChild(obj);

//create a new line break object (<br/>)
obj=document.createElement("br");
                        
//add the object to the form
frm.appendChild(obj);

When the popup appears I try append the previously input values but to no avail. The way I try to make it is the following:

obj.value=fileNamesArray[i];

where the fileNamesArray variable holds all the file names to be uploaded. I am sure there are filenames in the array since in the beginning of the for loop I have an alert box and it displays the file names correctly:

alert(fileNamesArray[i]);

Any help is more than welcome.