This small JavaScript function will convert any number from 1 to 9999 into a Roman Numeral - simply enter the number you wish to convert into the text box and submit.
Please note that the Romans did not have an agreed symbol for 5000 - in this version, all thousand values are represented using m. There are a few different ways to write 5000 and higher in numerals, such as I⊃⊃, v (the horizontal bar indicates that the character's value is multiplied by 1000) and mmmmm (used here). The latter is the most web-friendly due to the use of a letter rather than an obscure symbol or styling, thus why it was chosen in this script.