printing hidden fields problem

[yoki]

Hello,

I'm trying to print an hidden field through a loop but can't seem to generate the right field name. Can someone help me?

Here is my bit of code:

for ($i=1; $i <= $number_rows; $i++)
print ("<input type=\"hidden\" name=\"co_aut'.$i.'_last_name\" value=\"$i\"/>");

If I check my source after the page is generated, I get the following:

<input type="hidden" name="co_aut.'1'.last_name" value="1"/>
<input type="hidden" name="co_aut.'2'.last_name" value="2"/>
<input type="hidden" name="co_aut.'3'.last_name" value="3"/>
<input type="hidden" name="co_aut.'4'.last_name" value="4"/>
<input type="hidden" name="co_aut.'5'.last_name" value="5"/>
<input type="hidden" name="co_aut.'6'.last_name" value="6"/>
<input type="hidden" name="co_aut.'7'.last_name" value="7"/>
<input type="hidden" name="co_aut.'8'.last_name" value="8"/>
<input type="hidden" name="co_aut.'9'.last_name" value="9"/>
<input type="hidden" name="co_aut.'10'.last_name" value="10"/>

When it should be:

<input type="hidden" name="co_aut1_last_name" value="1"/>
<input type="hidden" name="co_aut2_last_name" value="2"/>
<input type="hidden" name="co_aut3_last_name" value="3"/>
<input type="hidden" name="co_aut4_last_name" value="4"/>
<input type="hidden" name="co_aut5_last_name" value="5"/>
<input type="hidden" name="co_aut6_last_name" value="6"/>
<input type="hidden" name="co_aut7_last_name" value="7"/>
<input type="hidden" name="co_aut8_last_name" value="8"/>
<input type="hidden" name="co_aut9_last_name" value="9"/>
<input type="hidden" name="co_aut10_last_name" value="10"/>

[Installer]

echo '<input type="hidden" name="co_aut' . $i . '_last_name" value="' . $i . '" />';