Formula to look and modify the data from another cell

Doubt.JPG

I have a data set as shown in the image in Colum A. I need to convert the abbreviation of the names in another colum as shown in Column B. I have totally 150 rows like this. SO it is difficult to do that manually. I tried with substitute(A1, "jhn","john"). It worked for the abbrviation with jhn. But not for the remaining. Then I tried with If(A1=jhn,Substitute(.....). It results in large argument. Need some suggestionjs to solve this. Thank you.

Dear Sir, Thanks for your reply. I tried but it is not met the need.
As per your instruction, I attached the sample workbook with exact need.
If it is possible kindly provide me suggestions or solution to solve the
attached file.

Thank you

Sir the output needs to be in Colum E. I copied the column A to column D, so, if someone downloaded the file then they can directly use the name manager for the two columsns. In column A the leading spaces are occured due to some error. I used trim comment. So, I eliminated the spaces. i.e. Trim(A1) gives the name without any leading spaces. After that If I used the step you provided in your previous reply, i.e. IFERROR(VLOOKUP....), it works nicely. When I tried to nest the formula, Error occurs. I would like to know how we can perform the operations (like eliminate the space infront the text, search for the abbreviated form in the column A, expand the actual name) using a single formula.
Thank you

Thanks sir, it worked properly. But why you used the trim in column D and also in Index formula. I am trying to learn this. But anyhow, the sample sheet what you provided is working perfectly. Thank you very much sir.

Thanks Mr. Glenn.
This is what I need exactly.