PHP Value of Variable is undefined - php

Question

I am getting " Notice: Undefined index:k" in the PHP code. K is the name of the text field and I am using $_GET[] method to get the value of k. In the below mentioned example I am trying to keep the value available even after the form is submitted. This Code runs fine for the first time but the second time it gives the above error.
<form name="keywordquery" method="get" action="keywordsearch.php">
<fieldset class="fieldsetclass"><legend class="legendclass">Search by
Keywords</legend>
<div id="searchbox">
<input type="text" name="k" value="<?php if(isset($_GET['k'])){echo
htmlentities($_GET['k']);} ?>" style="border: 1px, thin; width:92%; "/> <input
type="image" style="margin-bottom: 0; margin-top: 2px;" src="search.png"
value="submit" />
</div>
</fieldset>
</form>
</div>
<table id="dataTable" cellpadding="0" cellspacing="0" border="1" style="border-
radius:20px; box-shadow: 9px 5px 8px #7E9044;">
<tbody>
<?php
// PAGINATION Code. check if the starting row variable was passed in the
URL or not
if (!isset($_GET['startrow']) or !is_numeric($_GET['startrow'])) {
//we give the value of the starting row to 0 because nothing was found in URL
$startrow = 0;
//otherwise we take the value from the URL
} else {
$startrow = (int)$_GET['startrow'];
}
$k1 = $_GET['k'];
$term = explode(" ", $k1);
$query = "SELECT * FROM data ";
foreach ($term as $each) {
$i++;
if($i==1)
{
$query .= "WHERE keywords LIKE '%$each%' ";
}
else {
$query .= " OR WHERE keywords LIKE '%$each%' ";
}
}
$query .= "LIMIT $startrow, 1";
$connection = mysql_connect("xxxx", "xxxxx","");
if(!$connection)
echo "No database connected";
$dbase = mysql_select_db("xxxxxxxx", $connection);
if(!$dbase)
echo "No datatable connected";
$ourquery1 = mysql_query ($query);
if(!$ourquery1)
echo "No query found";
$row1 = mysql_num_rows ($ourquery1);
if ($row1 > 0)
{
while($result = mysql_fetch_assoc($ourquery1))
{
echo "<tr>";
$title = $result['title'];
$link = $result['link'];
$region = $result['region'];
$sector = $result['sector'];
$theme = $result['theme'];
echo "<td> <a href=$link><h3>$title<h3></a>";
echo "<h4>Sector: $sector
Theme: $theme
<br> Region: $region </td>";
}
}
echo "</tbody>";
echo 'Next';
echo 'Prev';

Answer 1

Replace the line:
$k1 = $_GET['k'];
with something like:
$k1 = isset($_GET['k'])? $_GET['k'] : $default_k_value;

Answer 2

You don't show the complete form so it is tough to tell what is wrong but here is a hint. Swap $_GET with $_REQUEST.
Example:
<?php if(isset($_REQUEST['k'])){echo
htmlentities($_REQUEST['k']);} ?>
If the form is using a POST method, the value would be in $_POST. If the form uses a GET method, the value would be in $_GET. However $_REQUEST will contain the form fields whether the form used POST or GET.