Hi, the problem is solved but can you help me, how can i rearrange the position of plot, i mean it should be SPI3, SPI6, SPI9 and SPI12 but the SPI12 comes out first.

df.m <- melt(testtukui, id.var = "MONTH")
ggplot(data = df.m, aes(x=variable, y=value)) + geom_boxplot(aes(fill=MONTH)) + ylab("SPI") + xlab(NULL)
this is my script.
and my data is like:
|MONTH|MODERATE|
|SPI3|-1.32|
|SPI3|-1.25|
|SPI3|-1.09|
|SPI3|-1.02|
|SPI3|-1.15|
|SPI3|-1.40|
|SPI6|-1.11|
|SPI6|-1.43|
|SPI9|-1.21|
|SPI9|-1.18|
|SPI12|-1.16|
|SPI12|-1.24|