错误消息：“异常：函数（”DressPerPrice“）不是此服务的有效方法”-SOAP Web服务

I'm trying to create a simple web service to retrieve the name of the dress(just for trying) based on the price inputted by the user but i'm getting the error message

Exception: Function ("DressPerPrice") is not a valid method for this service

I did some research and i found that it could be because of cache but in my server i have already specified to disable caching:

The server.php file:

<?php

header("Cache-Control: no-cache");

header("Pragma: no-cache");

require_once('dbconnect.class.php');
require_once('PriceHandler.class.php');

dbconnect::initialise();

ini_set("soap.wsdl_cache_enabled","0"); //disable caching
$server = new SoapServer('http://localhost/WebService/UDDI/90210Store.wsdl');

$server->setClass('PriceHandler');
$server->setPersistence(SOAP_PERSISTENCE_REQUEST);

$server->handle();

dbconnect::close();
?>

The WSDL 90210Store.wsdl:

<?xml version="1.0" encoding="UTF-8"?>

<definitions targetNamespace="http://www.shehzad.edu/webservice" xmlns:http="http://schemas.xmlsoap.org/wsdl/http/"
xmlns:mime="http://schemas.xmlsoap.org/wsdl/mime/" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/"
xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:this="http://www.shehzad.edu/webservice" xmlns="http://schemas.xmlsoap.org/wsdl/" xsi:schemaLocation="http://schemas.xmlsoap.org/wsdl/ http://schemas.xmlsoap.org/wsdl/wsdl.xsd http://www.w3.org/2001/XMLSchema http://www.w3.org/2001/XMLSchema.xsd">

<types>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="http://www.shehzad.edu/webservice" elementFormDefault="qualified">
<xs:element name="Input" type="xs:string"/>
<xs:complexType name="DressType">
     <xs:sequence>
         <xs:element name="Name" type="xs:string"/>
         <xs:element name="Price" type="xs:integer"/>
     </xs:sequence>
</xs:complexType>

<xs:complexType name="ArrayOfDresses">
     <xs:sequence>
         <xs:element name="DressPerPrice" minOccurs="1" maxOccurs="unbounded" type="this:DressType"/>
     </xs:sequence>
</xs:complexType>
<xs:element name="Result" type="this:ArrayOfDresses"/>
</xs:schema>
</types>

<!--input message-->
<message name="getDressPerPriceRequest">
     <part name="input" element="this:Input"/>
</message>

<!--output message-->
<message name="getDressPerPriceResponse">
     <part name="result" element="this:Result"/>
</message>

<portType name="DressPerPricePortType">
     <operation name="viewDressPerPrice">
         <input message="this:getDressPerPriceRequest"/>
         <output message="this:getDressPerPriceResponse"/>
     </operation>
</portType>

<binding name="DressPerPriceBinding" type="this:DressPerPricePortType">
     <soap:binding style="document" transport="http://schemas.xmlsoap.org/soap/http"/>
     <operation name="viewDressPerPrice">
         <soap:operation soapAction="http://www.shehzad.edu/webservice"/>
         <input><soap:body use="literal"/></input>
         <output><soap:body use="literal"/></output>
     </operation>
</binding>

<service name="DressPerPriceService">
     <port name="DressPerPricePort" binding="this:DressPerPriceBinding">
         <soap:address location="http://localhost/WebService/Server/Server.php"/>
     </port>
</service>

The class which keeps the method/function used by the server(PriceHandler.class.php):

<?php

class PriceHandler{

public function dressPerPrice($param)
{
    $sql = "SELECT (name,price) FROM product WHERE
            price LIKE '%".$param."%';";

    $db_result = mysql_query($sql);
    if(!db_result)
    {
        echo ("Query failed: ".mysql_error());
    }

    $ns = "http://www.shehzad.edu/webservice";

    $dressPerPrice = array();
    $result = array();

    if(mysql_num_rows($db_result) > 0)
    {
        while($row = mysql_fetch_assoc($db_result))
        {
            $dressPerPrice[] = array('Name' => $row['name'] , 'Price' => $row['price']);
        }
        mysql_free_result($db_result);
        $result = array('DressPerPrice'=>$dressPerPrice);
    }
    return $result;
}
}
?>

The category.html file(where the form is):

<!DOCTYPE HTML>
<html>
<head><h1>Dresses</h1></head>
<body>
 <p>
 <center>
  <table border="1" style="border-collapse:collapse;">
    <form id = "get_dress" action="Client.php" method="post">
        <tr><td colspan="2">
            <h3><center>Getting dresses per price</center></h3>
            </td>
        </tr>
        <tr><td>Enter field to search for: </td> 
            <td><input type="text" name="search_input"></td>
        </tr>
        <tr style="text-align:center;"><td colspan="2"><input type="submit" value="SUBMIT" name="submit"></td></tr>
    </form>
  </table>
 </center>
 </p>
</body>
</html>

If you need any other codes please let me know.

I don't really know what could be causing the error. I'm new to web services please be lenient. Thanks.