You can hide a form field in Microsoft CRM using javascript by using the following snippet:
crmForm.all.schemaName_c.style.display = 'none';
crmForm.all.schemaName_d.style.display = 'none';
Just be sure to replace “schemaName” in the above example with your own field.
The “_c” postfix denotes the table cell containing the label for the field while the “_d” postfix is the table cell which contains the actual input controls.
To make a field visible again, you can use the following:
crmForm.all.schemaName_c.style.display = 'inline';
crmForm.all.schemaName_d.style.display = 'inline';