InfoPath Dev

I have 3 sets of 2 (Yes, No) radio buttons on a form (IP 2007).  Depending on the combination of results, I want to set a value in a fourth text field.  Radio button are set with data type boolean; value = 1 (for Yes selection) and value= 0 (for No selection).

For example

if

radio button #1 = Yes

radio button #2 = Yes

radio button #3 = No

then

txtField4 = "Value1"  

Corresponding rule on txtField4 property is: if txtField4 is blank and rdo1 = 1 and rdo2 = 1 and rdo3 = 0 then set value of txtField4 = "Value1". 

I can't get it to work with one condition yet

I found a solution although it doesn't make sense to me and I am leary that something weird is going to happen later.  I had to set the exact same rules on each control to make it work.  And interestingly enough, the value that is display in my txtField4 comes from the rule placed in the txtField4 rule.  I named the values slightly different for each control to see which one controled the display value. 

I still would appreciate anyone's comments on why this only works like this.

Rules only execute when the field they are attached to changes its value.  If the user could change the radio buttons in any order, then all of the radio button fields will need to have rules.  Or you could put the rules on a button or something that the user clicks after selecting the option buttons.

Rules on a field that never gets modified will never execute.  That's why the txtField4 rule only executes when some other field changes the value on txtField4 (I'm presuming that's what's happening here).

Oh I see that makes sense!  I thought about using a button to set the text field value after the radio selections are set but I didn't want to make the user do more work.  Thank you for explaining this to me.