I have data formatted as in the dataex below.
What I want is to create one variable that will combine the A B C D E if they are "Yes", but I want the new variable to give the names of the combined variables.
for example, the new variable for id 12 would have "A, C", id 14 would have "A, B, C", and id 30 would have "B, C, D"
Is there a quick way of doing this, or do I have to write a lot of 'replace' code for the combinations?

Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input float id str3(A B C D E)
  1 "Yes" ""    ""    ""    ""   
  2 ""    ""    "Yes" ""    ""   
  3 ""    ""    "Yes" ""    ""   
  4 ""    ""    "Yes" ""    ""   
  5 ""    ""    "Yes" ""    ""   
  6 "Yes" ""    "Yes" ""    ""   
  7 ""    ""    "Yes" ""    ""   
  8 ""    ""    "Yes" ""    ""   
  9 ""    ""    "Yes" ""    ""   
 10 "Yes" ""    "Yes" ""    ""   
 11 ""    ""    "Yes" ""    ""   
 12 "Yes" ""    "Yes" ""    ""   
 13 "Yes" "Yes" "Yes" "Yes" ""   
 14 "Yes" "Yes" "Yes" ""    ""   
 15 "Yes" ""    "Yes" ""    ""   
 16 ""    ""    "Yes" ""    ""   
 17 ""    "Yes" "Yes" ""    ""   
 18 ""    ""    "Yes" ""    ""   
 19 ""    ""    "Yes" ""    ""   
 20 "Yes" "Yes" "Yes" "Yes" ""   
 21 "Yes" ""    "Yes" ""    ""   
 22 ""    ""    "Yes" ""    ""   
 23 ""    ""    "Yes" ""    ""   
 24 "Yes" "Yes" "Yes" "Yes" ""   
 25 ""    ""    "Yes" ""    ""   
 26 ""    ""    "Yes" ""    ""   
 27 ""    "Yes" "Yes" ""    ""   
 28 ""    "Yes" "Yes" ""    ""   
 29 ""    ""    "Yes" ""    ""   
 30 ""    "Yes" "Yes" "Yes" ""   
 31 "Yes" "Yes" "Yes" ""    ""   
 32 ""    ""    "Yes" ""    ""   
 33 ""    ""    "Yes" ""    ""   
 34 "Yes" "Yes" "Yes" ""    ""   
 35 ""    ""    ""    ""    ""   
 36 ""    ""    "Yes" ""    ""   
 37 "Yes" "Yes" "Yes" "Yes" ""   
 38 ""    ""    "Yes" ""    ""   
 39 "Yes" "Yes" "Yes" ""    ""   
 40 "Yes" "Yes" "Yes" ""    ""   
 41 "Yes" "Yes" "Yes" ""    ""   
 42 "Yes" ""    "Yes" ""    ""   
 43 "Yes" "Yes" "Yes" ""    ""   
 44 "Yes" "Yes" "Yes" ""    ""   
 45 "Yes" "Yes" "Yes" ""    ""   
 46 "Yes" "Yes" "Yes" "Yes" ""   
 47 "Yes" "Yes" "Yes" ""    ""   
 48 "Yes" "Yes" "Yes" ""    ""   
 49 "Yes" "Yes" "Yes" "Yes" ""   
 50 "Yes" "Yes" "Yes" ""    ""   
 51 "Yes" "Yes" "Yes" "Yes" ""   
 52 "Yes" "Yes" "Yes" ""    ""   
 53 "Yes" "Yes" "Yes" ""    ""   
 54 "Yes" "Yes" "Yes" ""    ""   
 55 ""    ""    "Yes" ""    ""   
 56 ""    ""    ""    ""    ""   
 57 "Yes" ""    "Yes" ""    ""   
 58 "Yes" "Yes" "Yes" ""    ""   
 59 "Yes" "Yes" "Yes" ""    ""   
 60 "Yes" "Yes" "Yes" ""    ""   
 61 "Yes" "Yes" "Yes" ""    ""   
 62 "Yes" "Yes" "Yes" ""    ""   
 63 "Yes" "Yes" "Yes" ""    ""   
 64 "Yes" ""    "Yes" ""    ""   
 65 "Yes" ""    "Yes" ""    ""   
 66 "Yes" "Yes" "Yes" "Yes" ""   
 67 "Yes" ""    "Yes" ""    ""   
 68 "Yes" "Yes" "Yes" ""    ""   
 69 "Yes" "Yes" "Yes" ""    ""   
 70 "Yes" "Yes" "Yes" ""    ""   
 71 "Yes" "Yes" "Yes" ""    ""   
 72 "Yes" "Yes" "Yes" ""    ""   
 73 "Yes" "Yes" "Yes" ""    ""   
 74 "Yes" "Yes" "Yes" ""    ""   
 75 "Yes" "Yes" "Yes" "Yes" "Yes"
 76 "Yes" "Yes" "Yes" ""    ""   
 77 "Yes" ""    "Yes" ""    ""   
 78 ""    ""    "Yes" ""    ""   
 79 "Yes" ""    "Yes" ""    ""   
 80 "Yes" "Yes" "Yes" ""    ""   
 81 "Yes" "Yes" "Yes" "Yes" ""   
 82 "Yes" "Yes" "Yes" ""    ""   
 83 "Yes" "Yes" "Yes" ""    ""   
 84 ""    "Yes" "Yes" ""    ""   
 85 ""    ""    ""    ""    ""   
 86 "Yes" "Yes" "Yes" ""    ""   
 87 "Yes" "Yes" "Yes" ""    ""   
 88 "Yes" ""    "Yes" ""    ""   
 89 "Yes" "Yes" "Yes" "Yes" ""   
 90 "Yes" "Yes" "Yes" "Yes" ""   
 91 "Yes" "Yes" "Yes" ""    ""   
 92 ""    ""    ""    ""    ""   
 93 ""    ""    ""    ""    ""   
 94 "Yes" ""    "Yes" ""    ""   
 95 "Yes" "Yes" "Yes" ""    ""   
 96 "Yes" ""    "Yes" ""    ""   
 97 "Yes" "Yes" "Yes" ""    ""   
 98 ""    ""    "Yes" ""    ""   
 99 "Yes" "Yes" "Yes" ""    ""   
100 ""    ""    "Yes" ""    ""   
end