In Opportunity view screen there will be a control in top right corner called "Change...". If you click on the control, you will see a menu like drop down. You can see options like "Stage...", "Won", "Future", "Lost...", "History".
Lets leave out Stage and History options for a moment. Other options are all related to Opportunity Status. If you click on status "Won" the current Opportunity's status will be changed to Won. If you click on "Future", the current Opportunity's status will be changed to Future. If you click on "Lost...", you will find another set of options, which are reasons for loosing the Opportunity. You need to select one among the options, once you select the Opportunity's status would be set to Lost and the reason you selected will be tied to the Opportunity. By deafualt upon registration you will have some reasons. If you want to add/remove reasons, go to System --> Custom data --> Opportunity lost reasons. You will find list of existing reasons, by selecting Add button on the list, you will be taken to add screen of the Opportunity lost reason. You can create the reasons which uits your business here.
In Opportunity view screen there will be a control in top right corner called "Change...". If you click on the control, you will see a menu like drop down. You can see options like "Stage...", "Won", "Future", "Lost...", "History".
Lets leave out Stage and History options for a moment. Other options are all related to Opportunity Status. If you click on status "Won" the current Opportunity's status will be changed to Won. If you click on "Future", the current Opportunity's status will be changed to Future. If you click on "Lost...", you will find another set of options, which are reasons for loosing the Opportunity. You need to select one among the options, once you select the Opportunity's status would be set to Lost and the reason you selected will be tied to the Opportunity. By deafualt upon registration you will have some reasons. If you want to add/remove reasons, go to System --> Custom data --> Opportunity lost reasons. You will find list of existing reasons, by selecting Add button on the list, you will be taken to add screen of the Opportunity lost reason. You can create the reasons which uits your business here.