adox append new column in accdb,name it by textbox string

Question

hello sir, 
 

  i m a beginner in c#, now i do ms access project using office 2007 and vs 2010/32 bit
/win 7/professional.

 using adox i want to add new column by append method, and want to name this column by textbox string or by string variable assigned dynamically,but keeping the previously created colums are undistrubed. i want to know that how many columns can be created in accesss 2007. and i here by attached my codings.

thank u sir,