Auto Volume according to entry price and take profit price

I need a script that can automatic calculate the volume needed for a trade to my desire take profit amount

Example:

I want to open pending order of buying EURUSD with the following prices. Take profit amount: $100.

To input:

Type of order to choose : (Buy Stop or Buy Limit or Sell Stop or Sell limit) - to choose from drop-down menu

Profit target: ($100) - to key in manually

Entry price: (1.10000) - to key in manually

Take profit: (1.10050) - to key in manually

Once key in the data, pending order will be open with volume calculated automatically. In this case it will be

" size: 2.0 / Entry Price: 1.10000 / Take profit: 1.10050 "

I am trading the following currency:

USD / JPY / CAD / NZD and others

Please take note that different currency have different price* (or size), the script must be able to calculate accordingly to my TAKE PROFIT AMT. if i want take profit $100, MEANS i want take profit $100. the size must be correct.

*example for a size 2.0, EURUSD is $20 per pip, but EURJPY will be around $17.73 per pip and EURCAD will be around  $16.06 per pip and EURNZD will be around $13.88 etc etc

Script must be able to auto calculate according to market price and NOT LIKE THE FOLLOWING:

Example (ERROR IN CALCULATION)

I want to open pending order of buying EURNZD with the following prices. Take profit amount: $100.

To input:

Type of order to choose : (Buy Stop or Buy Limit or Sell Stop or Sell limit) - to choose from drop-down menu

Profit target: ($100) - to key in manually

Entry price: (1.10000) - to key in manually

Take profit: (1.10050) - to key in manually

If the pending order is as below, IT WILL BE WRONG !!!!!!!!!!!!!!!

" size: 2.0 / Entry Price: 1.10000 / Take profit: 1.10050 "