vb.net - Loading text into a list box -

the main goal need achieve make details entered user (such minutes used , total cost etc.) shown user in 1 list once boxes have been filled out. able save text within box/listbox txt file on pc.

that pretty need do. cant seem happen , have no idea of how can that. code have far works how should.

public class form1     private sub form1_load(sender object, e eventargs) handles mybase.load     end sub      private sub btn1totalcost_click(sender object, e eventargs) handles btn1totalcost.click          'declaring variables.         dim minutesallowed integer         dim minutesused integer         dim textsallowed integer         dim textsused integer         dim dataallowed integer         dim dataused integer         dim minutestotalcost double         dim textstotalcost double         dim datatotalcost double         dim monthlycost double         dim totalcost double          minutesallowed = val(txtboxminutesallowed.text)         minutesused = val(txtboxminutesused.text)         textsallowed = val(txtboxtextsallowed.text)         textsused = val(txtboxtextsused.text)         dataallowed = val(txtboxdataallowed.text)         dataused = val(txtboxdataused.text)         minutestotalcost = val(txtboxtotalcost.text)         textstotalcost = val(txtboxtotalcost.text)         datatotalcost = val(txtboxtotalcost.text)         totalcost = val(txtboxtotalcost.text)          'calculation minutes         minutesallowed = val(txtboxminutesallowed.text)         minutesused = val(txtboxminutesused.text)         monthlycost = val(txtboxmonthlycost.text)         'if minutes allowed greater or equal minutes used, no charge added.         if minutesallowed >= minutesused             minutestotalcost = 0         else 'if minutes used greater minutes allowed, each minute multiplied 00.30p.             minutestotalcost = (minutesused - minutesallowed) * 0.3         end if         txtboxtotalcost.text = ctype(minutestotalcost + monthlycost, string)            'calculation texts         textsallowed = val(txtboxtextsallowed.text)         textsused = val(txtboxtextsused.text)         monthlycost = val(txtboxmonthlycost.text)         'if texts allowed greater or equal texts used, no charge added.         if textsallowed >= textsused             textstotalcost = 0         else 'if texts used greater texts allowed, each text multiplied 00.15p.             textstotalcost = (textsused - textsallowed) * 0.15         end if         txtboxtotalcost.text = ctype(textstotalcost + monthlycost, string)            'calculation data         dataallowed = val(txtboxdataallowed.text)         dataused = val(txtboxdataused.text)         monthlycost = val(txtboxmonthlycost.text)         'if data allowed greater or equal data used, no charge added.         if dataallowed >= dataused             datatotalcost = 0         else 'if data used greater data allowed, 10.00 added total cost.             datatotalcost = 10         end if         txtboxtotalcost.text = ctype(datatotalcost + monthlycost + textstotalcost + minutestotalcost, double)     end sub end class 

ok. code brutally honest isn't good. these lines

dim fullname string dim phonenumber decimal dim accnumber decimal dim minutesallowed integer dim textsallowed integer dim dataallowed integer dim minutesused integer dim textsused integer dim dataused integer dim monthlycost double dim totalcost double 

are declaring variables of specific types - strings,decimals , integers , on. means can accept values same type. having option strict on in code correct these errors show errors have code. these lines should be:

fullname = "" phonenumber = 0d accnumber = 0d minutesallowed = 0 textsallowed = 0 dataallowed = 0 minutesused = 0 textsused = 0 dataused = 0 monthlycost = 0r totalcost = 0r 

the reason you're having problems can't assign empty string integer or other number. option strict on, these errors show up. incidendtally better declaring phonenumber string allow dashes , brackets etc. if totalcost double monthlycost should double

the letters after numbers indicate type of number being asssigned. d means it's decimal 0 , r means it's double 0. in code stands, when variables declared, assigned default values anyway, don't need lines assigning values

moving on ..

listbox.items.add("full name: " + txtboxfullname.text) listbox.items.add("phone number: " + txtboxphonenumber.text) 

and on

the lines above unrelated the variable declarations above. intentional? example txtboxfullname.text isn't same variable fullname @ , unless have other code, dont see need above variables. i'm guessing code you've posted incomplete. when you're posting question, need post relevant code. have here .. https://stackoverflow.com/help/mcve

listen plutonix - wise.