BOM lines issue

Hi Everyone,

we have bill of materials form (BOM) in that click lines button open bom lines form in ax 2009.This BOM lines form data i have in excel sheet .I want to import that excel sheet data to bom lines.but i already imported that data to bom lines form but error came.

that error is dimension number is already exist . actually this dimension no filed is in inventdim table field.

how to solve this error?

can u tell me this solution?

thanks advance