Add 'oncontextmenu' event handler

[Issue#]   N_SE-50017
[Problem]  String characters can be pasted into the number input box.
[Cause]    This was not handled.
[Solution] 'oncontextmenu' event handler is added, so as not to allow the paste menu.

Change-Id: Ie3c7dae1372479a2f07cef04282634022550fee6

diff --git a/index.html b/index.html
index f56e651..cb1f431 100755 (executable)
--- a/index.html
+++ b/index.html
@@ -22,7 +22,7 @@
     <hr />
    </hgroup>
   </header>
-  <p>Enter the matrix length : <input type="number" min="100" max="300" value="100" id="length_btn" onkeydown="check_input_onkeydown()" style="height: 30px; width: 70px" /> (100~300)<br /></p>
+  <p>Enter the matrix length : <input type="number" min="100" max="300" value="100" id="length_btn" onkeydown="check_input_onkeydown()"  oncontextmenu="return false;" style="height: 30px; width: 70px" /> (100~300)<br /></p>
   <hr />
   <div id="resultByJS_div">
     Javascript :