Sliding door structure

A sliding door structure coupled to a casing having therein a receiving space, a port received in the receiving space, a first opening formed at the casing, and a first guide rail fixed to the casing to face the receiving space and positioned proximate to the first opening, the sliding door structure comprising:

• a frame body disposed in the receiving space, having a second guide rail and a resilient arm, and formed with a second opening corresponding in position to the first opening, wherein the resilient arm is disposed at the frame body and positioned proximate to the second opening;
• and
• a door body disposed between the casing and the frame body and having a first sliding portion, a second sliding portion, and at least a stop portion, the first sliding portion being slidably engaged with the first guide rail, the second sliding portion being slidably engaged with the second guide rail so as to allow the door body to slide along the first guide rail and the second guide rail and thereby selectively block or unblock the first opening and the second opening, wherein the resilient arm abuts against the at least a stop portion to enable the door body to be positioned stepwise.