Problem with adding items to lists

[soryjero]

hello, i am coding a program but i have a problem with it.

 

i have defined a list of items and a item of the same class of the list to read a item and add it to list. i read it and i add it to list. first time is everything ok but if i read it more times, first item i add is the same as second. i mean if for example first item is value 1 and second is value 3, when i read first time item value of list is 1 but second time, both elements of the list are 3.

i dont know why this can be happen.

 

Could anyone help me please?