Hi. well doing an application and need to test for if the text box is empty. and heres' my code below. so how to do that. i use the is not numeric, and if i click on the calculate button, it then does the calculation it should throw up an error. if i do is numeric, and click the calculate button, get the error. if i put in a title for the text box. say for example, terminator. the application i am doing in my book, is a video rental project. and you have a title text box, radio buttons to choose the format, check boxes for new members and new releases, and a rental amount text box and buttons. so here's the sample code, and can any one help me out. had not to do much with conversion of strings for my text box. and so getting the error, and does not calculate the current rental amount, and the discount amount as well. so, tried looking on msdn , and using the CStr function. so will put my string conversion expression. can any one help me out? cheers Marvin. ps: had not much to do with converting strings. or just maybe use the strTitle = integer.parse(tbTitleTextBox.Text) and then have the message box, underneath. so here's the code: If IsNumeric(tbTitleTextBox.Text) Then strTitle = CStr(tbTitleTextBox.Text) Else MessageBox.Show("You Did Not Enter A Valid Text Value For Movie Title.", "Data Error", _ MessageBoxButtons.OK, MessageBoxIcon.Exclamation) tbTitleTextBox.Focus() Return End If E-mail: startrekcafe@xxxxxxxxx MSN: sttartrekcafe@xxxxxxx Skype: startrekcafe We Are The Borg! You Will Be Assimilated! Resistance Is Futile! Star Trek Voyager Episode 68 Scorpian Part One E-mail: startrekcafe@xxxxxxxxx MSN: sttartrekcafe@xxxxxxx Skype: startrekcafe We Are The Borg! You Will Be Assimilated! Resistance Is Futile! Star Trek Voyager Episode 68 Scorpian Part One __________ View the list's information and change your settings at //www.freelists.org/list/programmingblind