How can I have a radio button selection grey out a drop menu option.

[Frank29897909hegs]

I have a form that one of the questions is Male or Female and a Radio button for each choice, after selecting Female I want a drop down menu that asks if Pregnant.  So I have put a drop down next to it with a Yes or No to select.  Obviously if you select male I want the drop down to be grey out or not able to select it.  Thank you in advanced for the help.

[Nesa Nurani · Accepted solution]

Let's say your choices in radio buttons are named "Male" and "Female" and your dropdown field is named "Pregnant,
use this as 'Mouse Up' action (Run a JavaScript) of "Male" radio button:
if(event.target.value == "Male")
this.getField("Pregnant").readonly = true;

use this as 'Mouse Up' action (Run a JavaScript) of "Female" radio button:
if(event.target.value == "Female")
this.getField("Pregnant").readonly = false;

[try67]

It might also be a good idea to reset the "Pregnant" field when "Male" is selected, just in case.

[Frank29897909hegs]

Thank you for your answer, however it gives me an error.  Im not sure if this makes a diference but the Male Femal Radio buttons and Pregnant drop down menu are part of a radio group called "Aplicant Gender".  

[Nesa Nurani]

What is the error you get?

[Frank29897909hegs]

Actullay I did a mistake it works, however if I select Female and also select yes or no, then l go back and select Male "Yes" or "No" is still displayed.

[Nesa Nurani]

What should be displayed? You said you only have "Yes" and "No" in dropdown, do you have a default value like empty space or something else?

[Frank29897909hegs]

I got it, there is a blank space option and I just realised that the mouse up can have 2 functions and one of them I set up is to reset the form but I de selected all and just maid it to reset "Pregnant", thanks alot!!