Merge multiple text files into one text file

Question

I have multiple text files .each file is named as s100041.asd.txt ,s100044.asd.txt ....... . Now each file contain   two fields such as

 

Wavelength   S100141.asd
325    0.015082292401682
326    0.011690540571175
327   1.06575414031349E-02
328   1.30298010496599E-02
329   0.014743817273513

 

 

another file 

 

Wavelength S100144.asd
325  1.35059549289737E-02
326  0.010981114226419
327  1.22348778870862E-02
328  1.63555124470031E-02
329  1.57389782659161E-02

 

 likewise i have lot of files in which wavelength is common and only  .asd field differ.

 

I want  to put one opendialog control through which I can select multiple files. as I select files all those files get  combined and result in one txt file and  output appears like this

 

 

 

 

S100144.asd	S100143.asd	S100142.asd	S100141.asd
0.013506	0.016867	0.011569	0.015082
0.010981	0.015599	0.009434	0.011691
0.012235	0.015259	0.010794	0.010658
0.016356	0.016275	0.014576	0.013030
0.015739	0.016134	0.013878	0.014744
0.014514	0.016259	0.012032	0.015209
0.015142	0.017304	0.011341	0.014354
0.015259	0.017318	0.012004	0.014129
0.014385	0.016048	0.012976	0.013645
0.012086	0.013314	0.012666	0.011062
0.012186	0.013723	0.012504	0.011287
0.014508	0.016509	0.012791	0.013942
0.015285	0.015257	0.013379	0.013823
0.014972	0.013261	0.013592	0.012550
0.014264	0.012519	0.013243	0.011364
0.016256	0.013304	0.013790	0.012205
0.018061	0.014753	0.014364	0.013313
0.015868	0.015758	0.013750	0.012321
0.014737	0.015407	0.013885	0.012425
0.014850	0.014171	0.014401	0.013287

 

 

 

i'm new to c# please  i need code for it .......