Проверка за празни полета

[karamel4o]

Как мога да направя една проверка дали полетата са празни ?

if($_POST['submit']){

$comment = htmlspecialchars($_POST['post_user_wall']);
$do = $user_id; 
$date = date("d");
$month = date("m");
$year = date("Y");
$time = date("H:i(worry)");
$our = mysql_query("SELECT id FROM comments_wall ORDER BY id DESC LIMIT 1"); 
while($r=mysql_fetch_array($our)){ 
}
if($profid == $user_id){
$sql1 = mysql_query("INSERT comments_wall (ot,date,month,year,time,comment,do) VALUES ('$profile[id]','$date','$month','$year','$time','$comment','$do')") or die(mysql_error());}else{
$sql = mysql_query("INSERT events (ot,do,cloas,date,month,year,time,view) VALUES ('$profile[id]','$do','stena','$date','$month','$year','$time','no')") or die(mysql_error());
$sql1 = mysql_query("INSERT comments_wall (ot,date,month,year,time,comment,do) VALUES ('$profile[id]','$date','$month','$year','$time','$comment','$do')") or die(mysql_error());
}
}
}else{echo'';}

 

[explozen]

if($_POST['submit']){

$comment = htmlspecialchars($_POST['post_user_wall']);
$do = $user_id; 
$date = date("d");
$month = date("m");
$year = date("Y");
$time = date("H:i(worry)");
if($month == NULL || $year == NULL)
{
echo "Моля въведете задължителните полета!";
}
$our = mysql_query("SELECT id FROM comments_wall ORDER BY id DESC LIMIT 1"); 
while($r=mysql_fetch_array($our)){ 
}
if($profid == $user_id){
$sql1 = mysql_query("INSERT comments_wall (ot,date,month,year,time,comment,do) VALUES ('$profile[id]','$date','$month','$year','$time','$comment','$do')") or die(mysql_error());}else{
$sql = mysql_query("INSERT events (ot,do,cloas,date,month,year,time,view) VALUES ('$profile[id]','$do','stena','$date','$month','$year','$time','no')") or die(mysql_error());
$sql1 = mysql_query("INSERT comments_wall (ot,date,month,year,time,comment,do) VALUES ('$profile[id]','$date','$month','$year','$time','$comment','$do')") or die(mysql_error());
}
}
}else{echo'';}

if($month == NULL || $year == NULL)
На този ред на мястото на mounth и year си задаваш полетата които да се проверяват