 Usage:  no=select1item(stitle,sitems,atitle)  
 
 Input:

  stitle                 string, menu title. 
                         
  sitems                 string vector, menu items. 
                         
  atitle                 optional, an alternative menu title if an error 
                         (no selection or more than 1 selection) occurred. 
                         
 Output:

  no                     number of selected item. 
                         
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(C) MD*TECH Method and Data Technologies, 17.8.2000
