BDC Error：Function code cannot be selected

add_bdcdata BdcTable, "RSPOSP01NR", "2000", "X", "", ""

add_bdcdata BdcTable, "", "", "", "BDC_CURSOR", "S_RQOWNE-LOW"

add_bdcdata BdcTable, "", "", "", "BDC_OKCODE", "=CRET"

add_bdcdata BdcTable, "", "", "", "S_RQOWNE-LOW", "20167757"

add_bdcdata BdcTable, "", "", "", "S_RQCRED-LOW", "2010/04/14"

add_bdcdata BdcTable, "", "", "", "S_RQCRED-HIGH", "2010/04/16"

add_bdcdata BdcTable, "", "", "", "S_RQCLIE-LOW", "800"

add_bdcdata BdcTable, "", "", "", "L_RQDEST-LOW", "CN36"

add_bdcdata BdcTable, "SAPMSSY0", "0120", "", "", ""

add_bdcdata BdcTable, "", "", "", "BDC_OKCODE", "=%PC"

错误出现在最后这个错误按钮上：=%PC 为什么呢？