try this
NPC Code:
// NPC made by unknown
// Hirathia Door Script
// Urond's Tavern
if (created) {
setimg newdoor.gif;
this.Door1 = 1;
}
if (playerchats && strequals(#a,Metal-Slug) && startswith(#c,Door)) {
message #c;
}
if (playerchats && strequals(#a,Metal-Slug) && strequals(#c,Door Closed)) {
this.Door1 = 1;
}
if (this.Door1 = 1 && playertouchsme) {
say2 Sorry
#bThis door is locked;
}
if (playerchats && strequals(#a,Metal-Slug) && strequals(#c,Door Opened)) {
this.Door1 = 0;
}
if (this.Door1 = 0 && playertouchsme) {
setlevel2 metal-slugbar.nw,30.5,57;
}
this seems like it should work