Thank you very much for your reply.
The answer is yes you can do it.
Please insert the following codes to your html codes.
<img src="captcha.php" border="0">
<input type="text" name="text" />
But to check the given number, you have to add my codes in "compare.php" to your desired form action php file.
(But in your code you didn't place a action php.So after submit your form it will do nothing)
Pleace change the form tag as follows,
<form action="compare.php" method="post">
After change all, you will get a code like this,
<form action="compare.php" method="post">
<table>
<tr>
<td>Name *</td>
<td><input type="text"></td>
</tr>
<tr>
<td>Email *</td>
<td><input type="text"></td>
</tr>
<tr>
<td>Phone</td>
<td><input type="text"></td>
</tr>
<tr>
<td>Field_check</td>
<td>
<input type="checkbox" value="1"><label>Check_1</label><br>
<input type="checkbox" value="2"><label>Check_2</label><br>
<input type="checkbox" value="3"><label>Check_3</label>
</td>
</tr>
<tr>
<td>Message *</td>
<td><textarea rows="5"></textarea></td>
</tr>
<tr>
<td colspan="2"> </td>
</tr>
<tr>
<td colspan="2"> </td>
</tr>
<tr>
<tr><td><img src="captcha.php" border="0"></td>
<td><input type="text" name="text" /></td>
<tr> <td><input type="button" id="subbut" value="Submit"></td>
</tr>
</table>
</form>
Please reply me the progress.
Good luck!!