i'm trying to select a set of depth values (points - ex. 2902, 2904, 2906, etc.)from surveyed points. save those to their own point layer, convert those to a TIN, then calc. Volumes. My approach was to make a list of the values, use those values as VARIABLES to create a series of shapefiles (shp2906, shp2908, etc.) then create TINs from those. Hard coding the numbers it works, but wanted to pass the depth values (using "select" (ex. grid_code le 2906)) name the shapefile and the tin (ex. tin2904, tin 2906, etc) was hoping to use the iteration as a variable, but it's not liking any of my attempts...... thanks in advance, for any ideas....