TypeError: document.getelementbyid(...) is null
<html> <head> <title>Port Scanner for Mozilla Firefox</title> </head> <body> <form name="my_form" id="my_form" method="post" action="#" onsubmit="return displayMessage();"> <p align="center">URL/Domain Name/IP Address: <input type="text" size="20" name="uri" value="" placeholder="http://www.google.com" required/></p> <table align="center" border="1" width=100% bgcolor="#f4fff0" bordercolor="green" cellspacing="2" cellpadding="2"> <tr> <td align="center"> Start port: <input type="text" size="5" name="start_port" maxlength="5"> End port: <input type="text" size="5" name="end_port" maxlength="5"><br> <input type="submit" value="Scan all ports" name="scan_all"><br> <input type="submit" value="Scan only open ports" name="scan_open"> </td> </tr> <tr> <td align="center"> <input type="text" size="20" name="scan_tcp"><br> <font color="#b1b1b1">Enter port numbers separated by space. (e.g. 21 25 80)</font><br> <input type="submit" value="Scan TCP ports" name="scan_tcp_ports"> </td> </tr> <tr> <td align="center"> <input type="submit" value="Scan common service ports" name="scan_common_tcp"><br> <input type="submit" value="Scan common Trojan ports" name="scan_common_trojan_tcp"> </td> </tr> </table> </form> <script type="text/javascript"> function displayMessage() { if(document.my_form.uri.value==0) { document.write("<font color='red'><i>Please enter URL/Domain Name/IP Address.</i></font>"); return false; } document.write("<DIV id='loading'><BR><BR><font color='#FF6600'><i>Please wait... The ports are being scanned...</i></font></DIV>"); document.getElementById("my_form").submit(); } window.onload=function() { document.getElementById("loading").style.display="none"; } </script> </body> </html>
I want to submit above form. But it shows me JavaScript error in Console that "TypeError: document.getelementbyid(...) is null" This error is for code : document.getElementById("my_form").submit();
I am using Firefox 24.0 and Windows 7. I have installed only 1 add-on. That is 'Firebug 1.12.3'. This code works fine for other browsers Except Firefox. Please help me to solve this problem.
Modified by cor-el
Chosen solution
Thank you very much. I could solve this error by using 'innerHTML' instead of document.write as it is deprecated.
Read this answer in context 👍 1All Replies (2)
It works fine for me...
Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).
To Enable SafeMode
- You can open Firefox 4.0+ in Safe Mode by holding the Shift key when you open the Firefox desktop or Start menu shortcut.
- Or open the Help menu and click on the Restart with Add-ons Disabled... menu item while Firefox is running.
- Once you get the pop-up, just select "'Start in Safe Mode"
If it works in Safe Mode and in normal mode with all extensions (Tools > Add-ons > Extensions) disabled then try to find which extension is causing it by enabling one extension at a time until the problem reappears.
Close and restart Firefox after each change via "Firefox > Exit" (Windows: Firefox/File > Exit; Mac: "Firefox > Quit Firefox"; Linux: "Firefox/File > Quit")
Chosen Solution
Thank you very much. I could solve this error by using 'innerHTML' instead of document.write as it is deprecated.