if (direction = "north") {
  x = currentroom.x
  y = currentroom.y + 1
  z = currentroom.z
}
else if (direction = "east") {
  x = currentroom.x + 1
  y = currentroom.y
  z = currentroom.z
}
else if (direction = "south") {
  x = currentroom.x
  y = currentroom.y - 1
  z = currentroom.z
}
else if (direction = "west") {
  x = currentroom.x - 1
  y = currentroom.y
  z = currentroom.z
}
create ("a" + x + "_" + y + "_" + z, "gen_" + direction)
create exit (direction + currentroom.name, direction, currentroom.name, "a" + x + "_" + y + "_" + z, direction + "direction")
MoveObject (player, "a" + x + "_" + y + "_" + z)

I get an error:
Error running script: Error compiling expression 'currentroom.name': RootExpressionElement: Cannot convert type 'String' to expression result of 'Element'

Here is my current game code (all of it) so you can see for yourself what I mean:

<!--Saved by Quest 5.6.5621.18142-->
<asl version="550">
  <include ref="English.aslx" />
  <include ref="Core.aslx" />
  <game name="Mazecraft">
    <gameid>0b09d9d0-9005-467a-b255-0ebb4cf2929a</gameid>
    <version>1.0</version>
    <firstpublished>2015</firstpublished>
  </game>
  <object name="a0_0_0">
    <inherit name="editor_room" />
    <beforefirstenter type="script">
      msg ("4")
    </beforefirstenter>
    <beforeenter type="script">
      msg ("1")
    </beforeenter>
    <enter type="script">
      msg ("2")
    </enter>
    <onexit type="script">
      msg ("3")
    </onexit>
    <firstenter type="script">
      msg ("5")
    </firstenter>
    <object name="player">
      <inherit name="editor_object" />
      <inherit name="editor_player" />
    </object>
    <exit alias="north" to="player">
      <inherit name="northdirection" />
      <runscript />
      <script type="script">
        going (this.alias, game.pov.parent)
      </script>
    </exit>
  </object>
  <type name="editor_room">
    <x type="int">0</x>
    <y type="int">0</y>
    <z type="int">0</z>
    <beforefirstenter type="script">
    </beforefirstenter>
    <firstenter type="script">
    </firstenter>
    <enter type="script">
    </enter>
    <onexit type="script">
    </onexit>
    <beforeenter type="script">
    </beforeenter>
    <changedparent type="script">
      if (game.pov = this) {
        if (IsDefined("oldvalue")) {
          OnEnterRoom ("oldvalue")
        }
        else {
          OnEnterRoom (null)
        }
        if (game.gridmap) {
          MergePOVCoordinates
        }
      }
    </changedparent>
    <visited type="boolean">false</visited>
  </type>
  <type name="gen_north">
    <inherit name="editor_room" />
  </type>
  <type name="gen_east">
    <inherit name="editor_room" />
  </type>
  <type name="gen_south">
    <inherit name="editor_room" />
  </type>
  <type name="gen_west">
    <inherit name="editor_room" />
  </type>
  <function name="going" parameters="direction, currentroom">
    if (direction = "north") {
      x = currentroom.x
      y = currentroom.y + 1
      z = currentroom.z
      direction2 = "south"
    }
    else if (direction = "east") {
      x = currentroom.x + 1
      y = currentroom.y
      z = currentroom.z
      direction2 = "west"
    }
    else if (direction = "south") {
      x = currentroom.x
      y = currentroom.y - 1
      z = currentroom.z
      direction2 = "north"
    }
    else if (direction = "west") {
      x = currentroom.x - 1
      y = currentroom.y
      z = currentroom.z
      direction2 = "east"
    }
    nextroom = ("a" + x + "_" + y + "_" + z)
    already_exist = GetObject(nextroom)
    if (already_exist = null) {
      create (nextroom, direction + "direction")
    }
    else {
      MoveObject (player, nextroom)
    }
  </function>
</asl>