在php中使用href传递多个变量

Am trying to send 2 variables from one page to another but in url i can see only one variable when i use &, but if i use ',' both variables are appear in thew url but in 2nd page if i tried to get the variables using $_GET[testid] both variables display,how to access 2 variables differently in 2nd page?

echo "<tr><td align=center ><a href=quiz.php?testid=$x[0]&subid=$x[3]><font size=4>$x[2]</font></a>";

in second page i use this code

$a=$_GET['subid'];
$b=$_GET['testid'];
echo $a;
echo $b;

the url in the next page

http://localhost/online/quiz.php?testid=187

It all gets a bit complicated when you have to use both single and double quotes

This should produce what you want

echo '<tr><td align="center"><a href="quiz.php?testid=' . $x[0] . '&subid=' . $x[3] . '"><font size="4">' . $x[2] . '</font></a>';
echo "<tr><td align=center >
<a href='quiz.php?testid=".$x[0]."&subid=".$x[3]."'>
  <font size=4>$x[2]</font>
</a>";