This is a double posting
which is against the forum rules. Please do not start a second thread on the same subject.
You have already had an answer in the first thread. I don't see why you have a problem with a decimal point, but there are so many errors that the code will not work at all.
You can enter a markup percentage as 30 and then divide that by 100 to get .3, add 1 to get 1.3 which you then multiply the first price by to get the uplifted price. Naturally you will need to check that the user does not enter .3 in the field!