sql join combine with condition

Please how to achieve following result from this data? (I am trying to combine join with conditions but still with some unwanted rows.)

Input is in one table only:

ID    IN    OUT
 1    6:00  null
 2    7:11  null
 2    null  16:30
 3    null  19:00

Output (a VIEW) should combine same IDs so the result will looks like:

ID    IN    OUT
1     6:00  null
2     7:11  16:30
3     null  19:00