onclick event function in JavaScript

Check you are calling same function or not.

<script>function greeting(){document.write("hi");}</script>

<input type="button" value="Click Here" onclick="greeting();"/>

Two observations:

1. You should write

   <input type="button" value="button text" />
   

   instead of

   <input type="button">button text</input>
   

2. You should rename your function. The function click() is already defined on a button (it simulates a click), and gets a higher priority then your method.

Note that there are a couple of suggestions here that are plain wrong, and you shouldn't spend to much time on them:

• Do not use onclick="javascript:myfunc()". Only use the javascript: prefix inside the href attribute of a hyperlink: <a href="javascript:myfunc()">.
• You don't have to end with a semicolon. onclick="foo()" and onclick="foo();" both work just fine.
• Event attributes in HTML are not case sensitive, so onclick, onClick and ONCLICK all work. It is common practice to write attributes in lowercase: onclick. note that javascript itself is case sensitive, so if you write document.getElementById("...").onclick = ..., then it must be all lowercase.

click() is a reserved word and already a function, change the name from click() to runclick() it works fine

Try this

<input type="button" onClick="return click();">button text</input>