ช่วยด้วยคะ เรื่องการ insert ข้อมูลมีปัญหารับค่าเป็นค่าว่างคะ

<meta http-equiv=Content-Type content="text/html; charset=utf8"> 

<form method = "POST" action = "manage.php?todo=insertplace">	
	<fieldset>
		<legend>เพิ่มสถานที่</legend>

			<div>
				<label> ID </label>	
				<input type = "text" name = "pid" >
			</div>	

			<div>
				<label> Name </label>	
				<input type = "text" name = "pname" >
			</div> 

			<div>
				<label> Info </label>	
				<textarea name = "info"> </textarea>
			</div>

			<div>
				<label> Catalog </label>	
				<?
					include "function1.php";
					catalog_select();
				?>
			</div>

			<div>
				<label> Picture </label>	
				<input type = "file" value = "Choose File" name = "pic" >
			 </div>

			<div>
				<label> Lattitude </label>	
				<input type = "text" name = "lat" >
			</div> 

			<div>
				<label> Longitude </label>	
				<input type = "text" name = "longitude" >
			</div> 	

			<div>
				<input type="submit" value ="submit" />  
				<input type="reset" value ="Clear" />
			</div>	
   

	</fieldset>	
</form>	

function catalog_select(){
	$dblink = connect_db ();
	$strSQL = " SELECT cid , cname FROM tbl_catalog ";
	$resultSQL 	 = mysqli_query($dblink,$strSQL);
	

		echo '<select cname ="cid">';
		echo '<option value=" "> เลือกหมวดหมู่</option>';

		while ($rows = mysqli_fetch_array($resultSQL)) 
			{


				echo '<option value= "'.$rows['cid'].'">'.$rows['cname'].' </option>';	


			}

		echo '</select>';
}

	if( $todo == 'insertplace' )	{ 

		$strSQL = "INSERT INTO tbl_placeinfo (pid, pname, info, cid, pic, lat , longitude) 
					VALUES ('$pid' , '$pname' , '$info' , '$cid' , '$pic' , '$lat','$longitude' ) ";	
					 
	$result	 = mysqli_query($dblink, $strSQL);


		if ($result){
			//echo 'Insert Complete';
			//echo '<meta HTTP-EQUIV =  "refresh" CONTENT =  "2; URL=placeinfoform.php">';
			echo $strSQL;	
		
		}
	else echo $strSQL;	
	}