Problem with data type Xstring

Hi

I have facing an issue when assigning string to X-String.

DATA : lv_string TYPE string,

             lv_xstring   type xstring.

lv_string = '128'.

lv_xstring = lv_string.

Lv_xstring value is getting changed to '1280' , Additionally zero is getting added , I have tried with many solutions.

How to avoid adding additional zero to lv_xstring fired.

But still facing the same issue.