Purchase order problem

While creating I am having the following problem

"No commitment item entered in item 00010 0001

Message no. FI311

Diagnosis

The posted document contains at least one company code in which Funds Management, Cash Budget Management, or Project Cash Management is active. Therefore you must enter a commitment item in all involved company codes.

Procedure

Enter a commitment item.

If you cannot enter a commitment item, check with your system administrator that your account assignment derivation is adjusted so that the system can automatically derive a commitment item from another account assignment, or from the G/L or cost element. "

Please suggest what to do now ?