Why loading this code need login?

I’ve written this piece of code and when I want to load it in WP admin I have to sign in again! what’s wrong?

<?php

function bedehkar_page() {

	global $pagenow, $wpdb;

	if($pagenow == 'admin.php' && $_GET['page'] == 'bedehkar' ){

//		$R_delete = @$_GET['delete_id'];
//
//		if(is_numeric($R_delete)){

//			$Check_Order = $wpdb->get_results("SELECT id FROM ".$wpdb->prefix."ticket_title WHERE id = '$R_delete'");
//
//			if($Check_Order){
//
//				foreach ($Check_Order as $row ) {
//					$Get_ID = $row->id;
//				}
//
//				$sql = $wpdb->query("DELETE FROM ".$wpdb->prefix."ticket_title WHERE id = '$R_delete'");
//
//				if($sql){
//
//					$sql = $wpdb->query("DELETE FROM ".$wpdb->prefix."ticket_body WHERE title_id = '$R_delete'");
//
//					if($sql){
//						$msg[] = "تیکت مورد نظر شما با موفقیت کامل حذف گردید";
//					}
//
//				}
//
//			}
//
//		}
//
		//======================================================================

		$Limit = "40";

		$R_page     = @$_GET['my-page'];
		$R_w_search = @$_POST['w_search'];
		$R_close    = @$_REQUEST['close'];

		$records = $wpdb->get_results("SELECT u.ID
											  FROM ".$wpdb->prefix."users AS u

											  LEFT JOIN ".$wpdb->prefix."usermeta AS m
											  ON u.ID = m.user_id

											  WHERE (u.user_email LIKE '%$R_w_search%') and m.meta_key='balance' and m.meta_value < 0");
		if($records){

			$R_this_page = $R_page;
			$Total_Rec   = $wpdb->num_rows;
			$Suffix      = "./admin.php?page=bedehkar&my-page=";

			list($R_this_page, $Total_page, $Limitvalue) = GetPageNumber ($R_this_page, $Total_Rec, $Limit);

			$Page_NeBa = ($Total_page != "1")? PageListNextBack ($R_this_page, $Total_page, $Limit, $Total_Rec, $Suffix) : "";

		}

		//Select Record
		//======================================================================

		$records = $wpdb->get_results("SELECT *
											  FROM ".$wpdb->prefix."users AS u

											  LEFT JOIN ".$wpdb->prefix."usermeta AS m
											  ON u.ID = m.user_id

											  WHERE (u.user_email LIKE '%$R_w_search%') and m.meta_key='balance' and m.meta_value < 0
                                                                                          ORDER BY convert( m.meta_value, decimal ) asc
											  LIMIT $Limitvalue, $Limit");

		$My_Record = "";

		if($records){

            $C = $Limitvalue;

			foreach ( $records as $record ) {

                $C++;

				$V_id              = $record->id;
				$V_user_id         = $record->user_id;
				$V_user_email      = $record->user_email;
				$V_user_balance    = $record->meta_value;

				$V_last_name       = get_the_author_meta( 'last_name', $V_user_id ); //Get name from wordpress db

				//===================================================

				//===================================================

				$Class = ($C % 2 == 0)? 'td_02' : 'td_01';

				//===================================================

				$My_Record .= "\n
				 			   <tr class='$Class'>

							   		<td height='35' align='center'>$C</td>

									<td height='35' class='title column-title'>
                                        <span>$V_last_name</span>
									</td>

									<td height='35' class='title column-title'>
                                        <span><a href=\"./user-edit.php?user_id=$V_user_id\" target=\"_blank\">$V_user_email</a></span>
									</td>

									<td height='35' class='title column-title'>
                                        <span>$V_user_balance</span>
									</td>

                      		   </tr>
							   \n";

			}

		}
		//========================================================================

?>		

   <style type="text/css">

	   a {
			text-decoration: none;
	   }

	   .title {
			font: bold normal 12px Tahoma, Geneva, sans-serif;
			color: #F00;
	   }

	   .star {
			color: #F00;
	   }

	   .normal {
	       font: normal 12px Tahoma, Geneva, sans-serif;
	       text-decoration: none;
	       color: #00F;
	   }

	   .blue {
	       color: #00F;
	   }

	   .green {
	       color: #090;
	   }

	   .red {
	       color: #F00;
	   }

	   .row-actions {
	       font: normal 11px Tahoma, Geneva, sans-serif;
	       margin-top: 10px;
	   }

	   .msg {
	       padding: 5px;
	       margin-top: 10px;
	       margin-bottom: 10px;
	       border: 1px solid #FFAEAE;
	       background: #FFECEC;
	   }

	   .wp-list-table thead {
		   background: #CCC;
	   }

	   .td_01 {
			background: #F9F9F9;
	   }

	   .td_02 {
			background: #FFF;
	   }

	   .link-box {
		   margin: 0px;
	   }

	   .link-box .item {
			float: right;
			width: 60px;
			height: 60px;
			border: 1px solid #D1D1D1;
			margin-bottom: 10px;
			margin-left: 30px;
			display:block;
			color:#fff;
	   }

   	   .link-box .item span{
			float: left;
			border: 1px solid linen;
			display:block;
			border-radius:5px;
			background:none repeat scroll 0 0 brown;
			color:#ffff;
			margin:3px;
			padding:1px;
	   }	   

	   .link-box .select-item {
	   		border: 1px solid #F00;
	   }

	   .link-box .link_06 {
		   background: url(<?php bloginfo('template_url'); ?>/images/list-icon.png) no-repeat -427px -2px;
	   }

	   .link-box .link_07 {
		   background: url(<?php bloginfo('template_url'); ?>/images/list-icon.png) no-repeat -513px -2px;
	   }

    </style>

	<table width="100%" border="0" cellspacing="1" cellpadding="1">

          <tr>
            <td height="25">
                <?php if(!empty($msg)){ ?>
 					 <div class="msg">
                	<?php
                    	foreach ($msg as $v => $k){
        					echo $k."<br />";
        				}
               		?>
                	</div>
            	<?php } ?>
            </td>
          </tr>

          <form action="admin.php?page=bedehkar" method="post">
          <tr>
            <td height="10">
            	<input name="w_search" type="text" value="<?php echo $R_w_search; ?>" />
                <input name="search-btn" type="submit" value="*جستجو" class="button-primary" />
            </td>
          </tr>
          </form>

          <tr>
            <td height="40">

                <table class="wp-list-table widefat fixed posts" cellspacing="0">
                  <thead>
                      <tr>

                      	<td height="40" width="40" align="center"><b>ردیف</b></td>

                        <td width="120"><b>نام کاربر</b></td>

                        <td width="170"><b>ایمیل</b></td>

                        <td width="150"><b>موجودی</b></td>

                      </tr>
                   </thead>

                   <tbody id="the-list">
                      <?php echo $My_Record; ?>
                   </tbody>

                </table>

            </td>
          </tr>

          <?php if($Total_page != "1"){ ?>
          <tr>
          	<td height="45" style="padding:2px 0px 0px 5px;" align="left"><?php echo  $Page_NeBa; ?></td>
          </tr>
        <?php  } ?>

    </table>

<?php 

	}

}

?>

GetPageNumber and PageListNextBack are simple functions for pagination.