diff --git a/lexicalStructure.lex b/lexicalStructure.lex
index 7857730..64b2863 100644
--- a/lexicalStructure.lex
+++ b/lexicalStructure.lex
@@ -81,6 +81,8 @@ SCHAR \\n|\\t|\\\"|[^\"\n\\]
 {ID}			{if(DEBUG) {printf( "ID:			%s	(%d)\n", yytext, ID);} 				else {return ID;}}
 
 \n				{line_number++; column_number = 1;}
-.				{column_number++;}
+\t				{column_number++;}
+" "				{column_number++;}
+.				{column_number++; return 1999;}
 
 %%
diff --git a/runner.c b/runner.c
index d170d26..dd096aa 100644
--- a/runner.c
+++ b/runner.c
@@ -80,6 +80,9 @@ int run(FILE *alpha) {
             }
             continue;
 	}
+   	if(token == 1999){
+                printf("On line number %d and column number %d we have an invalid character:%s\n",line_number,column_number,yytext);
+                }
 	column_number += yyleng;
     }