c# - get value from dynamic Textbox -

i hava arrays save controls. when call function initialize arrays , save in arrays controls.

code:

private label[] lblname;     private textbox[] txtname;     private label[] lblsurname;     private textbox[] txtsurname;     private label[] lblinstitution;     private textbox[] txtinstitution;     private label[] lblcountry;     private textbox[] txtcountry;     private label[] lblemail;     private textbox[] txtemail;     private placeholder placeholder1;       public int numberofotherauthors()     {         int32 index = convert.toint32(numberlist.selectedvalue);         return index;     }      public void guiofotherauthor()     {         int authors;         int = 0;         int j = 1;           authors = numberofotherauthors();         lblname = new label[authors];         txtname = new textbox[authors];         lblsurname = new label[authors];         txtsurname = new textbox[authors];         lblinstitution = new label[authors];         txtinstitution = new textbox[authors];         lblcountry = new label[authors];         txtcountry = new textbox[authors];         lblemail = new label[authors];         txtemail = new textbox[authors];         placeholder1 = new placeholder();           (i = 0; < authors; i++)         {             label authorinformation = new label();             authorinformation.text = "information author " + j.tostring() + " :";              lblname[i] = new label();             lblname[i].text = "name:";             txtname[i] = new textbox();             lblsurname[i] = new label();             lblsurname[i].text = "surname:";             txtsurname[i] = new textbox();             lblinstitution[i] = new label();             lblinstitution[i].text = "institution:";             txtinstitution[i] = new textbox();             lblcountry[i] = new label();             lblcountry[i].text = "country:";             txtcountry[i] = new textbox();             lblemail[i] = new label();             lblemail[i].text = "email:";             txtemail[i] = new textbox();              placeholder1.controls.add(new literalcontrol("<table>"));             placeholder1.controls.add(new literalcontrol("<span style=\"font-weight:bold;\" "));             placeholder1.controls.add(authorinformation);             placeholder1.controls.add(new literalcontrol("</span>"));             placeholder1.controls.add(new literalcontrol("<tr><td>"));             placeholder1.controls.add(lblname[i]);             placeholder1.controls.add(new literalcontrol("</td><td>"));             placeholder1.controls.add(txtname[i]);             placeholder1.controls.add(new literalcontrol("</td></tr>"));             placeholder1.controls.add(new literalcontrol("<tr><td>"));             placeholder1.controls.add(lblsurname[i]);             placeholder1.controls.add(new literalcontrol("</td><td>"));             placeholder1.controls.add(txtsurname[i]);             placeholder1.controls.add(new literalcontrol("</td></tr>"));             placeholder1.controls.add(new literalcontrol("<tr><td>"));             placeholder1.controls.add(lblinstitution[i]);             placeholder1.controls.add(new literalcontrol("</td><td>"));             placeholder1.controls.add(txtinstitution[i]);             placeholder1.controls.add(new literalcontrol("</td></tr>"));             placeholder1.controls.add(new literalcontrol("<tr><td>"));             placeholder1.controls.add(lblcountry[i]);             placeholder1.controls.add(new literalcontrol("</td><td>"));             placeholder1.controls.add(txtcountry[i]);             placeholder1.controls.add(new literalcontrol("</td></tr>"));             placeholder1.controls.add(new literalcontrol("<tr><td>"));             placeholder1.controls.add(lblemail[i]);             placeholder1.controls.add(new literalcontrol("</td><td>"));             placeholder1.controls.add(txtemail[i]);             placeholder1.controls.add(new literalcontrol("</td></tr>"));             placeholder1.controls.add(new literalcontrol("</table><br /> "));             panel1.controls.add(placeholder1);              j++;         }     } 

now want take value of textboxes in function public void uploadform(){...}. try it

int i; int numberofotherauthors = numberofotherauthors();  for(i=0; i<numberofotherauthors; i++) {    string = txtname[i].text } 

the textboxes values want upload database, let's save them string. when this, have nullreferenceexception. how value of textboxes??? thanks

i noticed uploadform() function referencing txtname, while actual textbox declared txtname. since field names case-sensitive, field "txtname" (lower-case 'n') not defined, cause of nullreferenceexception in dynamic page.