Help need in reporting Service

Hi All,
i am facing a problem, and looking for advice.

I have 2 text box
name : txt1
value : abc

name txt2
value : ddd

so, my txt2 value will be the value of itselft + the underline value txt1
i.e Final value = dddabc

i need to use expresssion to do this, so did any one know how to to it?

i manage to concatenate the the value, but the abc value is not underline.
concatenate by writing expression in txt2 = > txt2.value & reportItems!txt1.value

anyone know the command in reporting service to underline a value?
:ehh: