10 ILCS 5/7-47
Before leaving the booth, the primary elector shall fold his primary ballot in such manner as to conceal the marks thereon. Such voter shall then vote forthwith by handing the primary judge the primary ballot received by such voter. Thereupon the primary judge shall deposit such primary ballot in the ballot box. One of the judges shall thereupon enter in the primary poll book the name of the primary elector, his residence and his party affiliation or shall make the entries on the official poll record as required by articles 4, 5 and 6, if any one of them is applicable.
Where voting machines or electronic voting systems are used, the provisions of this section may be modified as required or authorized by Article 24 or Article 24A, whichever is applicable.
10 ILCS 5/7-47