problem with importing tilesets

[paulclip]

hi guys.. im kinda new in rpg maker and i recently downloaded some resources. when i imported those resources to RMXP, something went wrong.. the tiles aren't working as they should be.. here's a screenshot:



as you can see, the side's of the tiles(the white part) should be transparent when i use them, but in the screenshot, they weren't.. (that's a fire extinguisher with a circle by the way, with the  edges supposed to have been transparent..)
i dont know exactly what to do, and um, you help will be very much appreciated. thanks 

[Deliciously_Saucy]

When you import anything, you must click on the colour that you want to be transparent. If clicked right, the colour will start to flash. Just re-import the tileset.