When I try to "Convert Ascii Data to LAS" using the ENVI LiDAR Toolkit, the toolkit does not seem to work well. When there are 3 ~ 6 columns of data in the ascii file, the output LAS file will only use the first 3 columns of data to create a LAS file, and no dialog would appear for me to do the "Data Selection": the LAS file with the same name to the input ascii file is created automatically. If there are 1 or 2 columns of data in the ascii file, an error would occur: % Subscript range values of the form low:high must be >= 0, If there are more than 6 columns in the ascii file, another error would occur: % READ_ASCII: Illegal field name: % Execution halted at:     READ_ASCII         783 D:\Program Files\ITT\IDL70\lib\read_ascii.pro %                                       CONVERTXYZTOLAS %                                       $MAIN$ Any suggestions about the using of "Convert Ascii Data to LAS"? Thanks! ENVI 4.5 IDL 7.0