1.  Self-proved will; witness not required.  If the will is self-proved pursuant to section 2-503, the will satisfies the requirements for execution without the testimony of any attesting witness upon the filing of the will and the acknowledgment and affidavits annexed or attached to it, unless there is evidence of fraud or forgery affecting the acknowledgment or affidavit; or  

2.  Will not notarized; attesting witness required.  If the will is witnessed pursuant to section 2‑502, subsection 1, paragraph C but not notarized or self-proved, the testimony of at least one of the attesting witnesses is required to establish proper execution if the witness is within this State, competent and able to testify. Proper execution may be established by other evidence, including an affidavit of an attesting witness. An attestation clause that is signed by the attesting witnesses raises a rebuttable presumption that the events recited in the clause occurred.