CA Service Management

Is it possible create a custom atribute radion button with conditional if the option choiced is negative or others, to show a text box?

Good Day Daniela.
 
Based on the information as provided sofar, I tend to say that what you want is 'functionality you wish for'.
In other words, you need to open an idea in this same community, to get it voted on and reviewed there after.
To see whether it would be possible to implement such, in a future release.
 
Should you decide to do so, then please fully explain in a kind of 'step-by-step' scenario or procedure, what it is that you want to accomplish.
 
For development to get to know how to further epxloit on this.
 
Thanks and kind regards, Louis van Amelsfort.

You could do one of the following:

1) Call ca_fdShowField() onClick of the appropriate radio(s) similar to the following to show the text field:

ca_fdShowField(ca_fd.formId,'txtf_1')

2) If you need to apply some logic, rather than calling ca_fdShowField(), you can invoke a custom JavaScript function onClick of the radio(s)  to check the selected radio, apply logic and then call ca_fdShowField/ca_fdHideField appropriately.

For more information on Catalog predefined JavaScript functions like ca_fdShowField() please refer to Administration > Tools > Links > Form Designer JavaScript API in addition to the following:

Use JavaScript Functions in Fields - CA Service Management - 14.1 - CA Technologies Documentation