Anyone willing to write a small peice of code for me?

[lisameansbusiness]

I am using easy discount What i need is a php code that says if order total before tax and shipping is greater than 150.00 minus 25.00 from total order then add tax and shipping

 

I also need to add a box to enter a cerain code and it will minus 10% from total order. Im only using one code so there will not be multiple codes just one

 

so if code equal true then minus 10% i just cant write it in php can anyone help me.