diff --git a/custrom_functions_you_can_override.lua b/custrom_functions_you_can_override.lua
index f4e2153..a989e20 100644
--- a/custrom_functions_you_can_override.lua
+++ b/custrom_functions_you_can_override.lua
@@ -188,3 +188,72 @@ yl_speak_up.input_fs_action_custom = function(player, formname, fields)
 				"button[2,0.5;1.5,0.9;back_from_error_msg;Back]"})
 end
 
+-----------------------------------------------------------------------------
+-- Custom preconditions and effects (functions; they have the type "evaluate")
+-----------------------------------------------------------------------------
+-- each entry in the table has the following format:
+-- key: for display in edit options dialog and dropdown menu,
+--	function_name: name of the function that shall be called
+--      description: long description of what the function does,
+--      param1_text: label for the input field for param1 (if empty, no input field is offered)
+--      param1_desc: mouseover text for the input field for param1
+--      ...
+--      param9_text: label for the input field for param1
+--      param9_desc: mouseover text for the input field for param1
+--
+-- preconditions:
+yl_speak_up.custom_functions_p_ = {}
+-- actions: (not yet used)
+yl_speak_up.custom_functions_a_ = {}
+-- results:
+yl_speak_up.custom_functions_r_ = {}
+
+-- example function for preconditions:
+yl_speak_up.custom_functions_p_[ "example func" ] = {
+	function_call = "yl_speak_up.custom_example_function",
+	description = "Describe here in short form what your function does.",
+	param1_text = "1. Parameter:",
+	param1_desc = "This is the value passed to the function as first parameter.",
+	param2_text = "2. Parameter:",
+	param2_desc = "This is the value passed to the function as second parameter.",
+	param3_text = "3. Parameter:",
+	param3_desc = "This is the value passed to the function as 3. parameter.",
+	param4_text = "4. Parameter:",
+	param4_desc = "This is the value passed to the function as 4. parameter.",
+	param5_text = "5. Parameter:",
+	param5_desc = "This is the value passed to the function as 5. parameter.",
+	param6_text = "6. Parameter:",
+	param6_desc = "This is the value passed to the function as 6. parameter.",
+	param7_text = "7. Parameter:",
+	param7_desc = "This is the value passed to the function as 7. parameter.",
+	param8_text = "8. Parameter:",
+	param8_desc = "This is the value passed to the function as 8. parameter.",
+	param9_text = "9. Parameter:",
+	param9_desc = "This is the value passed to the function as 9. parameter.",
+}
+
+-- example function for results/effects:
+yl_speak_up.custom_functions_r_[ "example func" ] = {
+	function_call = "yl_speak_up.custom_example_function",
+	description = "Describe here in short form what your function does.",
+	param1_text = "1. Parameter:",
+	param1_desc = "This is the value passed to the function as first parameter.",
+	param2_text = "2. Parameter:",
+	param2_desc = "This is the value passed to the function as second parameter.",
+	param3_text = "3. Parameter:",
+	param3_desc = "This is the value passed to the function as 3. parameter.",
+	param4_text = "4. Parameter:",
+	param4_desc = "This is the value passed to the function as 4. parameter.",
+	param5_text = "5. Parameter:",
+	param5_desc = "This is the value passed to the function as 5. parameter.",
+	param6_text = "6. Parameter:",
+	param6_desc = "This is the value passed to the function as 6. parameter.",
+	param7_text = "7. Parameter:",
+	param7_desc = "This is the value passed to the function as 7. parameter.",
+	param8_text = "8. Parameter:",
+	param8_desc = "This is the value passed to the function as 8. parameter.",
+	param9_text = "9. Parameter:",
+	param9_desc = "This is the value passed to the function as 9. parameter.",
+}
+
+
diff --git a/fs_edit_general.lua b/fs_edit_general.lua
index e96f6ac..b6217dd 100644
--- a/fs_edit_general.lua
+++ b/fs_edit_general.lua
@@ -1635,9 +1635,35 @@ end
 yl_speak_up.get_fs_edit_option_p_and_e_evaluate = function(
 			pname, dialog, formspec, data, id_prefix, save_button, e,
 			text_select_operator, values_operator, check_operator)
-	if(e) then
-		data.function_name = e[ id_prefix.."value"]
-		-- TODO: p_param1 .. p_param9
+	local func_data = nil
+	if(e or true) then
+		--data.function_name = e[ id_prefix.."value"]
+		data.function_name = "example func"
+		-- TODO: create the dropdown
+		func_data = yl_speak_up["custom_functions_"..id_prefix][data.function_name]
+		-- add the fields for param1..param9:
+		if(func_data) then
+			local xoff = 0
+			for i = 1, 9 do
+				if(i > 5) then
+					xoff = 10
+				end
+				local paramn = "param"..tostring(i)
+				local s = func_data[paramn.."_text"]
+				if(s) then
+					formspec = formspec..
+						"label["..(0.2 + xoff)..","..(6.05 + ((i-1)%5)*0.8)..";"..
+							minetest.formspec_escape(s).."]"..
+						"field["..(4.0 + xoff)..","..(5.8 + ((i-1)%5)*0.8)..
+							";5.0,0.6;set_"..paramn..";;"..
+							minetest.formspec_escape(
+								data[paramn] or "- enter value -").."]"..
+						"tooltip[set_"..paramn..";"..
+							minetest.formspec_escape(
+								func_data[paramn.."_desc"] or "?").."]"
+				end
+			end
+		end
 	end
 	local operator_list = {}
 	for i, v in ipairs(check_operator) do
@@ -1660,11 +1686,11 @@ yl_speak_up.get_fs_edit_option_p_and_e_evaluate = function(
 		text_operator_and_comparison..
 		-- TODO: rather a dropdown...
 		"field[1.0,4.8;5.0,0.6;property;;"..
-			minetest.formspec_escape(data.property or "- enter name -").."]"..
-		"hypertext[1.2,7.0;16.0,2.5;some_text;<normal>"..
-			"<b>Note:</b> Functions are called with parameters which are passed on to them. "..
-			"The function then calculates a result. This can be compared to a given value."..
-			"</normal>]"
+			minetest.formspec_escape(data.property or "- enter name -").."]"
+--		"hypertext[1.2,7.0;16.0,2.5;some_text;<normal>"..
+--			"<b>Note:</b> Functions are called with parameters which are passed on to them. "..
+--			"The function then calculates a result. This can be compared to a given value."..
+--			"</normal>]"
 end
 
 
diff --git a/fs_edit_preconditions.lua b/fs_edit_preconditions.lua
index 7f46939..b9fd9e9 100644
--- a/fs_edit_preconditions.lua
+++ b/fs_edit_preconditions.lua
@@ -247,7 +247,7 @@ yl_speak_up.show_precondition = function(p, pname)
 	elseif(p.p_type == "evaluate") then
 		local str = ""
 		for i = 1, 9 do
-			str = str..tostring(p["p_param" + str(i)])
+			str = str..tostring(p["p_param" + tostring(i)])
 			if(i < 9) then
 				str = str..","
 			end