>I try to replace a numeric field with str() but not work,

You can't replace a numeric field with string. VFP should raise an error. Even If You replace if WITH VAL(STR(account_sum,16,0)) If the field is defined with two decimal places it always appears with 999999.99 format. If You want to change the way how it appears on form/report... You must change the inputmask propertie of the control that shows that field.