Adding new record

[MimiSD]

Currently in my database I have a many to many relationship between a
tblSchool (primary key: SchoolCode) and tblIssue (primary key: IssueID). The
junction table that allows the many to many relationship is called
tblSchlIsse and holds the primary key from both tables. I have created a
form off of the two tables that allows a representative to enter a new issue
when it is reported by a school. The school information is then in a subform
so that if more than one school calls in on the same issue it can keep track
of all schools having the same issue. Right now down in the subform if I
type in a school code that is already in the table the corresponding
information will fill. Where i run into a problem is when a new school who
has not previously reported any issues calls in. In the subform you can type
in the information of that school but then the error "The Microsoft Jet
Database engine cannot find a record in the table 'tblSchool' with key
matching field(s) 'School code'." How can i get around this error and just
have it add the information if it is not found?