Just for anyone curious:
The above map will hide the "cf_1440" (obviously change it with you own) only when creating a new asset.
PHP Code:
<map>
<originmodule>
<originname>Assets</originname>
</originmodule>
<dependencies>
<dependency>
<field>asset_no</field>
<condition>
[{
"groupid": "",
"columnname": "vtiger_assets:assetname:assetname:Assets_Asset_Name:V",
"comparator" : "e",
"value": "",
"columncondition": ""
}]
</condition>
<actions>
<hide>
<field>cf_1440</field>
</hide>
</actions>
</dependency>
</dependencies>
</map>
The above map will hide the "cf_1440" (obviously change it with you own) only when creating a new asset.