i followed the example on the book "calling c from IDL" .I test it on the vc++6.0 then it succeed! But when I try to use the same way on platform vs2008 ,then it didn't work! It always give the error tips as follows: IDL> simpleProcedure % SIMPLEPROCEDURE: Error loading sharable executable. Symbol: IDL_Load, File = D:\Program Files\ITT\IDL71\bin\bin.x86\simpleExample.dll Õ?»µ½?¶¨µ?ÌÐò¡£ % Execution halted at: $MAIN$ Can anybody tell me why I failed!!