The PHP if statement determines if my query is empty

<?PHPHeader("content-type:text/html; Charset=utf-8 ");$username=$_get[' username '];$PSW=$_get[' Password '];$phone=$_get[' Phone '];include(".. /ini/inid.php ");$select _admin=mysql_query("SELECT count (*) c from ofuseradmin where phone= '".$phone."‘ ");//determines whether the empty while($sa=Mysql_fetch_array($select _admin)){if($sa[' C ']== ' 0 '){    mysql_query("INSERT into Ofuseradmin (username,password,phone) VALUES (')."$username."‘,‘".MD5($PSW)."‘,‘".$phone."‘)");$aid=mysql_query("SELECT * from Ofuseradmin where phone= '".$phone."‘"); while($aids=Mysql_fetch_array($aid)){//echo $aids [' Aid '];//echo <br> ';Echo"<input type= ' text ' value= '".$aids[' Aid ']. "' id= ' pid ' name= ' aid ' > ';}}//Add StatementElse{//echo "This combination already exists! "; Echo"<script>alert (' This phone number already exists! '); History.go ( -1);</script> "; }//include (".. /ini/inid.php ");} ?>

The PHP if statement determines if my query is empty