how to add table row that contains 2 select option, select option which is connected to the database to filter the data out in other select options.

Hi guys need some guidance PHP + javascript..

I am having trouble creating the form PHP and javascript, I have a form which contains some information that should be filled in by the user.

in the form, I have 2 select option.
Fyi, that select option use the database.
second select option is dependent to select option first. Or Dynamically populate dropdown dependent on another dropdown using databases.

what i want to do is, every user who enter data will create one ticket number. and one ticket number can have more than one product and request.

select option first is for PRODUCT
second select option is for REQUEST

if only one request and one product for one ticket number, I can easily enter information into the database without any error

but if there is a user who has more than one PRODUCT & REQUEST, then with the help of javascript I add table rows containing select option according to user requirement. This section is also very easy, I can add table row as user demand

but when a table row is increased, the state began uncomfortable, I can not select the information that is in the select option, an error message appears, makes me very sad

is there anything that can give me instructions to resolve this mess ???, it's almost a month but do not know how to fix that code..

to clarify information from the image above, I will explain briefly:

  1. Picture number 1 is the position where there are no additional rows of the table (the default state)
  2. see the plus and minus, useful to add or delete table rows
  3. Figure 2 looks select option still functions normally
  4. Figure 3 illustrates the case of the addition of table rows by pressing the "+" (C)
  5. If the point c, the "+" is already in the press then it will look like a point C, rows, increasing user demand
  6. the latter is the figure 4, describes the error message that appears when a table row is growing ..
  7. error that show is: "errors on this webpage might cause it to work" incorrectly
  8. 'document.frmPost.subcat.options.length' is null or not an object, indexip.php line 68
  9. 'document.frmPost.subcat.options.length' is null or not an object, indexip.php line 68 char 5 code 0