Multimap output files problems

[Web_Sailor]

Hi. :-/
I am trying to create multiple output files while reading a single input file. The multiple files will be created based on the value in the first field.

My set1 contains 1,2,3,2,1,3. That is Field1 values.
My multimap contains the other fields (field2 and field3).
Now what I am trying to do is to use ofstream to output multiple output files dynamically. Its just creating 1 file and duplicating records :sad:

Here is my input file:-

1	AAAAAA	BBBBBB    
2	DDDDDD	EEEEEE
3	GGGGGG	HHHHHH
2	NNNNNN	LLLLLL
1	UUUUUU	KKKKKK  
3	SSSSSS  BBBBBB

This is how I expect my output to be:-

file1.txt:
1	AAAAAA	BBBBBB
1	UUUUUU	KKKKKK

file2.txt:
2	NNNNNN	LLLLLL
2	DDDDDD	EEEEEE

file3.txt:
3	GGGGGG	HHHHHH
3	SSSSSS  BBBBBB

Here is my code so far:-

set1.insert(field1);
     for(itv=set1.begin(); itv !=set1.end(); itv++)

     {
       if(chr.compare(*itv)==0){
          string filenamei = "myfile";
          multimap<string,string> mmi;
          ofstream out;
          mmi.insert (pair<string,string>(band,start));
          out.open(filenamei.c_str());
       for (it= mmi.begin(); it != mmi.end(); it++){

              cout << (*it).first << "\t" << (*it).second << endl;
       }
       
       }//end of if loop
     }

Thanks :X