How do i get the variable values to show up in the table usi

How do i get the variable values to show up in the table using echo? It is currently only showing me the variable name when being displayed.

<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Strict//EN\"
\"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd\">
<?php # Script 1.8 - paycheck.php

// Set the variables:
$firstname = $_REQUEST[\'firstName\'];
$lastname = $_REQUEST[\'lastName\'];
$hours = $_REQUEST[\'hours\'];
$hourlyrate = $_REQUEST[\'hourlyrate\'];
$ficarate = 5.65;
$federalrate = 5.75;
$staterate = 28;

$employeename = $firstname . \",\". $lastname;
$regularpay = $hours * $hourlyrate;
$overtime = $hours - 40;
$overtimepay = ($overtime * 1.5) * $hourlyrate;
$grosspay = $regularpay + $overtimepay;
$statetax = ($staterate / 100) * $grosspay;
$federaltax = ($federalrate / 100) * $grosspay;
$ficatax = ($ficarate / 100) * $grosspay;//
$totaltax = ($ficarate + $staterate + $federalrate) ;
$netpay = ($grosspay - $totaltax);

#firstname check

if(empty($_REQUEST[\'firstname\']))

{ $firstname=NULL;

echo \'You Must enter a first name\';

}

else{$firstname=$_REQUEST[\'firstname\'];

}

#lastname check

if(empty($_REQUEST[\'lastname\']))

{ $lastname=NULL;

echo \'Please enter a last name\';

}

else{$lastname=$_POST[\'lastname\'];

}

# hourly rate check
if(empty($_REQUEST[\'hourlyrate\']))

{ $hoursworked=NULL;

echo \'You must enter an Hourly Rate that is between 7.25 and 100.00\';

}

elseif ($_REQUEST[\'hourlyrate\']<0 || $_REQUEST[\'hourlyrate\']>100)

{

echo \' You must enter an Hourly Rate that is between 7.25 and 100.00.\';

$hourlyrate=NULL;

}

else{$hourlyrate=$_POST[\'hourlyrate\'];

}

if (empty($_REQUEST[\'hourlyrate\'])) {
$rhw = NULL;
echo \'You forgot to enter your hourly rate!\';
}
elseif ($_REQUEST[\'hourlyrate\'] < 0 || $_REQUEST[\'hourlyrate\'] > 100)
{

echo \'You need to enter an hourly rate between 0 and 100\';
$rhw = NULL;
}
else { $hourlyrate = $_POST[\'hourlyrate\'];
$hours = number_format ($hours,2);
$regularpay = number_format($regularpay,2);
$overtimepay = number_format ($overtimepay, 2);
$overtime = number_format ($overtime, 2);
$hourlyrate = number_format ($hourlyrate,2);
$ficarate = number_format($ficarate, 2);
$ficatax = number_format ($ficatax,2);
$staterate = number_format($staterate,2);
$statetax = number_format($statetax,2);
$federalrate = number_format($federalrate, 2);
$grosspay = number_format($grosspay, 2);
$netpay = number_format($netpay, 2);
$totaltax = number_format($totaltax,2);

echo \"<table>
<tr>
<th colspan=>Paycheck Calculator</th>
</tr>
<tr>
<td>Employee Name</td>
<td>\"<?php echo \"$employeename\"; ?>\"</td></tr>
<tr>
<td>Regular Hours Worked (between 0 and 40)</td>
<td>$hours</td></tr>
<tr>
<td>Overtime Hours Worked(between 0 and 40)</td>
<td>$overtime</td></tr>
<tr>
<td>Regular Pay</td>
<td>$$regularpay</td></tr>
<tr>
<td>Overtime Pay</td>
<td>$$overtimepay</td>
</tr>
<tr>
<td>Gross Pay</td>
<td>$grosspay</td></tr>
<tr>
<td>Fica Tax Rate</td>
<td>$ficarate%</td>
</tr>
<tr>
<td>Fica Taxes Withheld</td>
<td>$ficatax</td>
</tr>
<tr>
<td>State Tax Rate</td>
<td>$staterate%</td>
</tr>
</tr>
<tr>
<td>State Taxes Withheld</td>
<td>$$statetax</td>
</tr>
<tr>
<td>Federal Tax Rate</td>
<td>$federalrate%</td>
</tr>
<tr>
<td>Federal Tax Withheld</td>
<td>$federaltax</td>
</tr>
<tr>
<td>Total Taxes</td>
<td>$totaltax</td>
</tr>
</tr>
<tr>
<td>Net Pay</td>
<td>$$netpay</td>
</tr>
</td>
</tr>
</table>\";
}

<html xmlns=\"http://www.w3.org/1999/xhtml\" xml:lang=\"en\" lang=\"en\">
<head>
<meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\">
<link rel=\"stylesheet\" href=\"css/styles.css\" type=\"text/css\">
<title>Numbers</title>
</head>
<body>

</body>
</html>

There is error in the way echo statement is written

you have written the echo statement as follows to print the variable name employeename <td>\"<?php echo \"$employeename\"; ?>\"</td></tr>

The correct way to write is as follows:

<td>$employeename</td></tr>

Use this way to print the employeename in your code and it will print the value not the variable name.