Indiana Code Title 31. Family Law and Juvenile Law § 31-21-5-6

Sec. 6. (a) Except as otherwise provided in section 4 of this chapter, an Indiana court may not exercise its jurisdiction under this article if, at the time of the commencement of the proceeding, a proceeding concerning the custody of the child has been commenced in a court of another state having jurisdiction substantially in conformity with this article, unless the proceeding:

(b) Except as otherwise provided in section 4 of this chapter, an Indiana court, before hearing a child custody proceeding, shall examine the court documents and other information supplied by the parties under sections 10 through 13 of this chapter.  If the court determines that a child custody proceeding has been commenced in a court in another state having jurisdiction substantially in accordance with this article, the Indiana court shall:

If the court of the state having jurisdiction substantially in accordance with this article does not determine that the Indiana court is a more appropriate forum, the Indiana court shall dismiss the proceeding.