Adding "" around variable

There is most likely a simple solution but how do I add " " around a variable?

This is code i'm using but I get an unexpected T_VARIABLE error.

Thanks.

PHP Code:

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function  registrations() { 
include("db_connect.php"); 

$query = mysql_query("SELECT * FROM mytable"); 
$results = mysql_fetch_row($query); 

while($Details = mysql_fetch_row($results)) { 

echo " "$Details[0]" <br>"; 

} 

} 


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Code:

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echo " \"$Details[0]\" <br>";

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