js implementation script with all capital letters in English_javascript skills

Complete code:

<form name="form"> <input type="text" name="box" value="type in here!"> <input type="button" value="Convert" onclick="javascript:changeCase(this.form.box)"> </form>
[Ctrl A Select all Note: If you need to introduce external Js, you need to refresh to execute

]

Script description:
Step 1: Add the following code to the area



Step 2: Add the following code In the area