Cannot mandatory on field using custom script

Hi during the customer input the customer and contact is a mandatory but customer should be created first before input so i create some kind of a workaround after the customer is created i create a custom script to make the field mandatory but when i use the script below it made the field automatically mandatory. can any1 check and see what i did wrong. thank you.

   if(frm.doc.workflow_state=="Draft") {
	frm.set_df_property("customer_tax_address", "reqd", 1);