How to Get the highest value of a recordset?

I have a table which looks like below:
id-----year-----month-----value
1-----2007--------9--------123
1-----2007--------8--------144
1-----2007--------7--------345
1-----2006-------12-------1448
3-----2007--------6--------123
3-----2007--------2--------144
3-----2006-------11--------345
3-----2006-------10-------1448

i need to get the highest year-month value of each id, e.g.
id-----year-----month-----value
1-----2007--------9--------123
3-----2007--------6--------123

how can i do it in sql?

thanks.