short foundword= 0, eraseamount= -1;
							
/* 
doesn't work in situation in which there are whitespaces after word 

Example: bar foo___(ctrl-backspace here)
Result should be bar_
but is bar foo___

_ is whitespace
*/
						
for(x=but->pos; x>=0; x--) {
  if(str[x] != ' ' && foundword == 0) /* there are other possibilities also? */
    foundword= 1;
  if(str[x] == ' ' && foundword == 1)
    break;
  eraseamount++;
}