ใครก็ได้ช่วยดูโค้ดนี้ให้ผมทีแก้ยังไงก็ไม่ได้ซักทีคับ

  <script> 
	function check()
	{
	  var lev_start_date =document.levtableform.start_date.value;
	  var lev_end_date=document.levtableform.end_date.value;
	  var lev_start_time=document.levtableform.type.value;
	  var lev_end_time=document.levtableform.type2.value;
	  var lev_medi=document.levtableform.medi.value;

	    if(lev_start_date=="")
		{
			alert("คุณไม่ได้เลือกวันที่เริ่มการลา  ( please input StartDate )");
		}
		else if(lev_end_date=="")
		{
			alert("คุณไม่ได้เลือกวันที่สิ้นสุดการลา ( please input EndDate )");
		}
		else if (lev_start_time=="")
		{
			alert("คุณไม่ได้เลือกเวลาเริ่มต้น ( please input StartTime )");
		}
		else if(lev_end_time=="")
		{
			alert("คุณไม่ได้เลือกเวลาสิ้นสุด ( please input EndTime )");
		}
		else if(lev_medi=="" );
		{
			alert('Please Click Radio Option ');
		} 
		else
		{

	}
	

	</script>
<?php include "head.php" ?>
	<script language="JavaScript" src="js/calendar_eu.js"></script>
	<link rel="stylesheet" href="css/calendar.css">
	<form name="levtableform" action="dosick.php" method="post">
	<table id="levtable" align="center">
		<tr><th colspan="4">ลาป่วย<br /></td></tr>
		<tr><td></td></tr>
		<tr><td></td></tr>
		<tr><td></td></tr>
		<tr><td></td></tr>
		<tr>
			<td>วันที่</td>
			<td><input type="text" name="start_date" id="start_date" />
				<script language="JavaScript">
				var o_cal = new tcal ({
				// form name
				'formname': 'levtableform',
				// input name
				'controlname': 'start_date'
				});

				// individual template parameters can be modified via the calendar variable
				o_cal.a_tpl.yearscroll = false;
				o_cal.a_tpl.weekstart = 1;
				</script></td>
			<td align="right">ถึงวันที่</td>
			<td><input type="text" name="end_date" id="end_date" />
			
				<script language="JavaScript">

				// whole calendar template can be redefined per individual calendar
				var A_CALTPL = 
				{
				'months' : ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'],
				'weekdays' : ['Su', 'Mo', 'Tu', 'We', 'Th', 'Fr', 'Sa'],
				'yearscroll': true,
				'weekstart': 0,
				'centyear'  : 70,
				'imgpath' : 'img/'
				}

				new tcal 
				({
				// if referenced by ID then form name is not required
				'controlname': 'end_date'
				}, A_CALTPL);
				</script>
			</td>
		</tr>

		<tr>
			<td>ตั้งแต่เวลา</td>
			<td><select name="type" id="type">
				<option selected="selected">กรุณาเลือก</option>
				<option>8:00</option>
				<option>13:00</option>
				</select>
			</td>
			<td align="right">ถึงเวลา</td>
			<td><select name="type2" id="type2">
				<option selected="selected">กรุณาเลือก</option>
				<option>13:00</option>
				<option>17:00</option>
				</select>
			</td>
		</tr>
		<tr>
			<td>ใบรับรองแพทย์</td>
			<td><input type="radio" name="medi" value="0" id="medi_0">มี</td>
			<td colspan="2"><input type="radio" name="medi" value="1" id="medi_1">ไม่มี</td>
		</tr>
		<tr>
			<td>สาเหตุการลา</td>
			<td colspan="4"><input type="radio" name="becu" value="head" id="becu">เป็นไข้ , ปวดหัว</td>
		</tr>
		<tr>
			<td></td>
			<td colspan="4"><input type="radio" name="becu" value="diar" id="becu">ท้องเสีย</td>
		</tr>
		<tr>
			<td></td>
			<td colspan="4"><input type="radio" name="becu" value="acci" id="becu">อุบัติเหตุ</td>
		</tr>
		<tr>
			<td></td>
			<td colspan="4"><input type="radio" name="becu" value="othe" id="becu">อื่นๆ</td>
		</tr>
		<tr>
			<td colspan="4" align="center"><input type="button" value="submit" name="sub" onclick="check()"/>
			<input type="reset" name="sub2" id="sub2" value="Reset" /></td>
		</tr>
	</table>
	</form>


<?php include "foot.php" ?>

อันนี้เป็นส่วนหน้าเว็บคับ


Code (PHP)
[php]<?php
	session_start();
	include "connect.php";
	conndb();
	$id = $_SESSION['emp_id'];
	
	$sdate = $_POST['start_date'];
	$sday = substr($sdate,0,2);
	$smonth = substr($sdate,3,2);
	$syear = substr($sdate,6,4);
	$smk=mktime(0, 0, 0, $smonth, $sday, $syear);
	$start_date = strftime('%Y-%m-%d',$smk);

	
	$edate = $_POST['end_date'];
	$eday = substr($edate,0,2);
	$emonth = substr($edate,3,2);
	$eyear = substr($edate,6,4);
	$emk=mktime(0, 0, 0, $emonth, $eday, $eyear);
	$end_date = strftime('%Y-%m-%d',$emk);



	$start_time = $_POST['type'];	
	$end_time = $_POST['type2'];
	$type = $_POST['type3']; 
	$detail = $_POST['Detail'];
	$last_lev_id = "";
	$medi = $_POST['medi'];
	

	$result = mysql_query("SELECT MAX(lev_id) FROM leaves");
	while($rs = mysql_fetch_array($result)){
		$last_lev_id = $rs['MAX(lev_id)']+1;
	}

	
	mysql_query("INSERT INTO `leaves` (`lev_id`, `lev_emp_id`, `lev_cod_id`, `lev_start_date`, `lev_end_date`, `lev_start_time`, `lev_end_time`, `lev_sub_id`, `lev_detail`, `lev_medi`) VALUES ('$last_lev_id','$id','sick','$start_date','$end_date','$start_time','$end_time','$type','$detail','$medi'");
	closedb();
	//header("Location:busi.php");

?>