Differentiate update request from Custom button and Save button

Hi,

I want to differentiate the update request from Custom button and standard save button.

i have created a custom button on a custom object and named as Refresh. whenever i click this button, the object data has to refresh and some processing will happen. i dont want to do the same process whenever i try to update that custom object (Save button). so i want to skip this processing while clicking the save button and have to do process only while clicking Refresh button.

I tried to update some field value on refresh button and checked that condition,i have added some SOQL before processing update record. So that field value checking wont work..

I tried to update a static value and checked it before executing code, but static value getting reset and am getting default value :(

suggest me idea :)