[ns] not able to make xgraph using awk scripts

[shubh]

awk scripts are running properly but not able to make xgraph
    i use commands:
     awk -f e2edelay.awk filename.tr > file.xgr
     xgraph file.xgr
    but it shows error that input is not valid.
    i have run these commands in many programs. awk scripts gives result
    but not able to make xgraph.
    please help me.