c# - To get total marks into a textbox -

my code is:

protected void txttotal_textchanged(object sender, eventargs e) {      int = convert.toint32(txtmaths.text);      int b = convert.toint32(txtsci.text);      int c = convert.toint32(txtenglish.text);      int tot = + b + c;      txttotal.text = convert.tostring(tot); }   

i trying total marks textbox, not working.can me please?

you trying change text in same textbox text changing, sure want do?

wouldn't want change total when maths,sci , english values change? if @ following.

protected void txtmaths_textchanged(object sender, eventargs e) {     updatetotals(); }  protected void txtsci_textchanged(object sender, eventargs e) {     updatetotals(); }  protected void txtenglish_textchanged(object sender, eventargs e) {     updatetotals(); }  protected void updatetotals()     {    int = convert.toint32(txtmaths.text);    int b = convert.toint32(txtsci.text);    int c = convert.toint32(txtenglish.text);    int tot = + b + c;    txttotal.text = tot.tostring(); }