I'm using DNN 4.9 and C#. The clientAPI works OK but there's one small issue. When accessing form variables I cannot get the value. Upon some investigation I found out that the Request does contain the control name but changes the underscores to dollar signes.So doing a Request[this.TexBox2.ClientID] won't find it.

More specifically the mentioned TextBox2 gets a client id of "dnn_ctr391_EditCreditDebitIncident_TextBox2" From DNN

The Request.form shows it as "dnn%24ctr391%24EditCreditDebitIncident%24TextBox2" as the Name

When getting form.AllKeys I get  "dnn$ctr391$EditCreditDebitIncident$TextBox2"

Anyone knows if its a Bug or if there's a solution

It does. I already figured it out. Was following the example from the Documentation which used ClientID (in VB). Thanks for your reply