You cannot use [value] like that as explained in your other topic. [value] will not give you the raw value of a field. It will give you the entirely processed with HTML included value. You'll need to use language overrides with the following language keys to have what you're wanting.
FIELD_FIELDIDHERE_TERMS_FIELD_I_AGREE_ON_THE_ABOVE_CONDITIONS
FIELD_FIELDIDHERE_TERMS_FIELD_ACCEPT_URL_CONDITIONS
Replace FIELDIDHERE with the actual ID of your field. For example you might have the following.
FIELD_39_TERMS_FIELD_I_AGREE_ON_THE_ABOVE_CONDITIONS
FIELD_39_TERMS_FIELD_ACCEPT_URL_CONDITIONS
Which of the above 2 you need depends on what mode the field is in. The first string is used if terms and conditions output is set to Text and the second is for URL based terms and conditions. Their default values are as follows.
Key: TERMS_FIELD_I_AGREE_ON_THE_ABOVE_CONDITIONS
Text: I Agree to the above [type].
Key: TERMS_FIELD_ACCEPT_URL_CONDITIONS
Text: Accept <a href=""[attributes]>[type]</a>
See the below on how to use language overrides.
www.joomlapolis.com/blog/kyle/18701-language-overrides-have-arrived