Autogenerated numbers skiiping few numbers while creating new objctct and increments also on error.

Hi everyone ,

I have custom form processor that create new WTPart from create wizard of  Document and number of part is same as document , so i have custom numbering schema in my customised OIR that gives me  editable generated number on wizard but problem is in preProcess() method it skips the few number while creating new Part which i don't want part number should be same as document number and one more condition is if i edit the number filed and the wrong numbers then i handeld the exception which helps me to do not create document but in this case in backend it autogenerates the number and increments that on error also which shoul be prevented ,
So how can we prevent the skiiping of number and increamenting of number on error using java code