Hi zahid.ansari, I created three fields named field1,field2 and field3. Field1 and field2 is text and field3 is option set. Then create a Web Resource whose type is JScript with the following code: function changeValue(executionContext){ var formContext = executionContext.getFormContext(); var optionSetValue = formContext.getAttribute(“new_field3”).getValue(); if(optionSetValue === 0){ formContext.getAttribute(“new_field2”).setValue(formContext.getAttribute(“new_field1”).getValue()); formContext.getControl(“new_field2”).setDisabled(true); }else if(optionSetValue === 4){ formContext.getControl(“new_field2”).setDisabled(false); }else{ //do something } } Finally, create a on load event and on change event on your form and using the above web resource as library. Result´╝Ť I created a new Account record: When field3 is set to Not Allowed: When field3 is set to Allowed: