--- capa/capa51/pProj/capaCommon.c	2004/06/01 19:57:18	1.24
+++ capa/capa51/pProj/capaCommon.c	2005/12/20 19:59:57	1.27
@@ -2454,7 +2454,8 @@ check_input_usymb(u_symb)char *u_symb;
 /*          num_p  : the numerical part in string */
 /*          unit_p : the unit string */
 /* num_p is used to calculate sig figs */
-/* return :   0  empty string          */
+/* return :  -1  invalid string        */
+/*            0  empty string          */
 /*            1  number without units  */
 /*            2  empty number with units */
 /*            3  number with units       */
@@ -2505,8 +2506,11 @@ char *buf;double *num; char *num_p; char
     
     e_part = 1.0;  /* default power */
     base_str[b_idx] = 0; /* initialize base_str[] */
-    while( isdigit(buf[idx]) || buf[idx] == '.' ) { /* should start with a digit or . */
+    if( buf[idx] == '1' && buf[idx+1] == '0') {
       base_str[b_idx++] = buf[idx++];
+      base_str[b_idx++] = buf[idx++];
+    } else {
+      return (-1);
     }
     base_str[b_idx] = 0; /* terminate base_str[] */
     while( isspace(buf[idx]) ) { idx++; } /* skip over white spaces */
@@ -2520,7 +2524,7 @@ char *buf;double *num; char *num_p; char
       while( isspace(buf[idx]) ) { idx++; }
       if( isdigit(buf[idx]) || buf[idx] == '+' || buf[idx] == '-' )  {
         exp_str[e_idx] = 0;  /* initialize exp_str[], again */
-        while( isdigit(buf[idx]) || buf[idx] == '.' || buf[idx] == '+' || buf[idx] == '-' ) {
+        while( isdigit(buf[idx]) /*|| buf[idx] == '.'*/ || buf[idx] == '+' || buf[idx] == '-' ) {
           exp_str[e_idx++] = buf[idx++];
         }
         exp_str[e_idx] = 0;  /* terminate exp_str[] */
@@ -2554,7 +2558,7 @@ char *buf;double *num; char *num_p; char
     while( isspace(buf[idx]) ) { idx++; }
     if( isdigit(buf[idx]) || buf[idx] == '+' || buf[idx] == '-' )  {
         exp_str[e_idx] = 0;
-        while( isdigit(buf[idx]) || buf[idx] == '.' || buf[idx] == '+' || buf[idx] == '-' ) {
+        while( isdigit(buf[idx]) /*|| buf[idx] == '.'*/ || buf[idx] == '+' || buf[idx] == '-' ) {
           exp_str[e_idx++] = buf[idx++];
         }
         exp_str[e_idx] = 0;
@@ -2565,6 +2569,9 @@ char *buf;double *num; char *num_p; char
     }
     sscanf(exp_str, "%lg", &e_part);
     sscanf(num_str, "%lg", &n_part);
+    if( n_part != 10 ) {
+      return (-1);
+    }
     result = pow(n_part,e_part);
     errcode = errcode | 1;
   } else {  /* number unit */
@@ -2927,7 +2934,7 @@ capa_check_ans(ai,ans, error) AnswerInfo
   char    *us;    /* ans_unit_str */
   Unit_t  *u_p;   /* ans_unit     */
   int      input_len, all_alphabet = 1, idx, ii, type;
-  int      outcome, result = INCORRECT;
+  int      outcome=-1, result = INCORRECT;
   int      sig, corr_len;
   int      choice[ANSWER_STRING_LENG];
   char     num_str[ANSWER_STRING_LENG], unit_str[ANSWER_STRING_LENG];
@@ -2953,8 +2960,10 @@ capa_check_ans(ai,ans, error) AnswerInfo
                 all_alphabet = 0;
               }
             }
-            if( !all_alphabet ) { /* answer string is not all alphabets */
+            if( !all_alphabet ) {
               outcome = split_num_unit(ans,&n_part,num_str,unit_str);
+	    }
+	    if( outcome > 0 ) {
               if( outcome > 1 ) { /* with both num and unit parts or only unit part */
                 if( u_p != NULL ) {
 		  result = check_correct_unit(unit_str,u_p,&scale);
@@ -3094,7 +3103,7 @@ capa_check_answer(p, answer, error) Prob
   char   *fmt;
   int     choice[ANSWER_STRING_LENG], correctans[ANSWER_STRING_LENG];
   int     ii, idx, corr_len, input_len;
-  int     result = INCORRECT, sig, outcome, all_alphabet;
+  int     result = INCORRECT, sig, outcome=-1, all_alphabet;
   char    fmted[FORMAT_STRING_LENG];
   double  given, target, ratio, fmted_target, target_u, target_l, scale=1.0;
   double  delta;
@@ -3122,6 +3131,8 @@ capa_check_answer(p, answer, error) Prob
             }
             if( !all_alphabet ) {
               outcome = split_num_unit(answer,&n_part,input,unit_str);
+	    }
+	    if( outcome > 0 ) {
               if( outcome > 1 ) { /* with both num and unit parts or only unit part */
                 if( p->ans_unit != NULL ) {
 		  result = check_correct_unit(unit_str,p->ans_unit,&scale);
@@ -3239,6 +3250,25 @@ capa_check_answer(p, answer, error) Prob
   return (result);
 }
 
+int check_tol (formula_val,tol_type,tol)
+double formula_val;int tol_type;double tol;
+{
+  double diff;
+  int outcome=APPROX_ANS;
+  if( tol_type == TOL_ABSOLUTE ) {
+    diff = tol - formula_val;
+    if( diff < 0.0 )  {
+      outcome = INCORRECT;
+    }
+  } else {
+    diff = fabs(1.0 - formula_val) * 100.0 ;
+    if( diff > tol ) {
+      outcome = INCORRECT;
+    }
+  }
+  return outcome;
+}
+
 /* -------------------------------------------------------------------------- */
 /*   assumming the formula is *fml_str and the student input is *input_str             */
 /*   according to the type of tolerance, we form the final formula as                  */
@@ -3251,7 +3281,7 @@ char *fml_str;char *input_str;char *var_
   char         *check_fml_str;
   int           f_len, i_len, outcome, error_code;
   PointsList_t *pt, *next;
-  double        formula_val, diff;
+  double        formula_val;
   
   f_len = strlen(fml_str);
   i_len = strlen(input_str);
@@ -3263,21 +3293,20 @@ char *fml_str;char *input_str;char *var_
     sprintf(check_fml_str,"(%s) / (%s)",input_str,fml_str);
   }
   outcome = APPROX_ANS;
+  if( pts_list==NULL ) {
+    error_code = f_eval_formula(&formula_val,check_fml_str, var_list, NULL);
+    if( ! error_code ) {
+      outcome = check_tol(formula_val,tol_type,tol);
+    } else {
+      outcome = BAD_FORMULA;
+    }      
+  }
+
   for(pt= pts_list; pt!=NULL ; pt=next) {
     next=pt->pts_next;
     error_code = f_eval_formula(&formula_val,check_fml_str, var_list, pt->pts_str);
     if( ! error_code ) {
-      if( tol_type == TOL_ABSOLUTE ) {
-        diff = tol - formula_val;
-        if( diff < 0.0 )  {
-          outcome = INCORRECT;
-        }
-      } else {
-        diff = abs(1.0 - formula_val) * 100.0 ;
-        if( diff > tol ) {
-          outcome = INCORRECT;
-        }
-      }
+      outcome = check_tol(formula_val,tol_type,tol);
     } else {
       outcome = BAD_FORMULA;
       break;