It's really no differant than receiving typed-in user input. Here's an example page that contains 1 text box. An employee scans his or her ID card, the form submits to itself, checks the value and then does other stuff based on other conditions. This should get you going:
<%Response.Buffer="true"%>
<!--#include file="connection.asp"-->
<!--#include File="Authenticate.asp" -->
<%
function GetLanID(username)
pos=instr(username,"\"

GetLanID=mid(username,pos+1)
end function
strName = request.servervariables("LOGON_USER"

strName = GetLanID(strName)
AuthUser()
IF AuthUser = FALSE then
response.Redirect("GotYa.asp?Page=EditPunch"

End IF
if request("flag"

<> "" then
flag=Request("flag"

else
flag=0
end if
PunchOut = FALSE
PunchIn = FALSE
%>
<html>
<head>
<title>Time Clock</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<style type="text/css">
th{font-family:tahoma;font-weight:bold;font-size:14px;}
td{font-family:tahoma;font-size:14px;}
h1{text-decoration:underline:font-family:tahoma;}
</style>
</head>
<body bgcolor="#FFFFFF" text="#000000">
<table align="center" width="100%" border="0">
<tr><td align="center"><h1>Fulfillment Time Clock</h1></td></tr>
</table>
<br><br><br><br>
<table width="50%" align="center" border="6" bordercolorlight="#F8BF24" bordercolordark="#000000" cellspacing="0" cellpadding="2">
<tr>
<th align="center">Please scan your ID card</th>
</tr>
<tr><td align="center">
<form name="input1" id="input1" action="<%=Request.ServerVariables("SCRIPT_NAME"

%>" method="post">
<input type="password" id="ScanValue" name="ScanValue" size="75" maxlength="75" >
<input type="hidden" name="flag" value="1">
</form>
</td>
</tr>
</table>
<script language="vbs">
input1.ScanValue.focus
</script>
<%If request("flag"

= 1 then
CardID = trim(cstr(request.form("ScanValue"

))
set conn=server.createobject("ADODB.CONNECTION"

conn.open myConnString
strSql = "SELECT EmpID, EmpName, Photo From tbl_c_Employees WHERE CardID = '" & CardID & "'"
set rs=conn.execute(strSql)
if not rs.eof then
if not isnull(rs("EmpID"

) then
EmpID = cint(rs("EmpID"

)
Photo = rs("Photo"

end if
EmpName = rs("EmpName"

response.write "<table align='center' border='0'><tr><td align='center'><font size='5'><br>" & EmpName & "<br><br><img src=" & Photo & " width='110' height='150'></td></tr></table>"
else
response.write "<table align='center' border='0'><tr><td align='center'><font color='red'>There is something wrong with your card.<br>Please see the administrator</td></tr></table>"
end if
set rs=nothing
strSql = "EXEC tc_sp_PunchTheClock @EmpID = " & EmpID & ",@UserID='" & strName & "'"
SET rs = Conn.execute(strSql)
InOrOut = rs(0)
myPunch = rs(1)
if InOrOut = 1 then ' Punching In
myVar = "In"
elseif InOrOut = 2 then ' Punching Out
myVar = "Out"
elseif InOrOut = 3 then ' Forgot to Punch Out
PunchOut = TRUE
myVar="Out"
elseif InOrOut = 4 then ' Forgot to Punch In
PunchIn = TRUE
end if
set rs=nothing
Conn.close
set conn=nothing
If PunchOut = TRUE then
response.write "<table align='center' border='0'><tr><td align='center'><font size='6'><b>You forgot to punch out yesterday. Please see the Administrator ASAP.</b></td></tr></table>"
elseif PunchIn = TRUE then
response.write "<table align='center' border='0'><tr><td align='center'><font size='6'><b>You forgot to punch IN Today. Please see the Administrator ASAP.</b></td></tr></table>"
else
response.write "<table align='center' border='0'><tr><td align='center'><font size='6'>" & "Punching <b><font color='#FF0000'>" & myVar & "</font><br>" & myPunch & "</b></td></tr></table>"
end if
end IF
%>
</body>
</html>