too long

Can anyone tell me if there is any error in the code. Because I think that $ _POST is not properly defined, because it didn't skips the first IF even when there is some value

for($i=1; $i<=15; $i++) {
    $hbs = "other_text".$i;

    if($_POST['other_text'.$i]]=="") { 
        echo "You didn't eneter quantity"; 
        die(); 
    }

    if(!is_int($_POST['other_text'.$i]) || isset($_POST['vin'.$i])) {
        $vins .= '<tr><td>'.$_POS['vin_lbl'.$i].'</td><td>'.$_POS['other_text'.$i].'</td></tr>';
    }
    else {
        echo "Incorrect data for quantity. 
 Please go back.";
    }
}

Now show me that Undefined index: other_text1 so i checked the form in html and this is the code of the textbox <input type="text" value="1" disabled name="other_text1" style="width:15px; padding:1px; height:10px; font-size:9px; background-color:#FFF; box-shadow:none; ">

Seem you have an extra closing bracket here

if($_POST['other_text'.$i]] <----

and your missing a semi colon here

echo "You didn't eneter quantity"; die() <-----

this script SHOULD look like

for($i=1; $i<=15; $i++) {
    $hbs = "other_text".$i;
    if($_POST['other_text'.$i]=="")
    {
      echo "You didn't eneter quantity"; die(); 
    }
    if(!is_int($_POST['other_text'.$i])|| isset($_POST['vin'.$i]))
    {
      $vins .= '<tr><td>'.$_POST['vin_lbl'.$i].'</td><td>'.$_POST['other_text'.$i].'</td></tr>';
    }
    else echo"Incorrect data for quantity. 
 Please go back.";
  }

Why there is an additional closing square bracket ]] ??

if($_POST['other_text'.$i]]==""){ echo "You didn't eneter quantity"; die() }

It should be

if($_POST['other_text'.$i]==""){ echo "You didn't eneter quantity"; die() }

You also have a spell mistake $_POS ?? it should be $_POST

$vins .= '<tr><td>'.$_POST['vin_lbl'.$i].'</td><td>'.$_POST['other_text'.$i].'</td></tr>';

Also remove de here after the loop