just search you ll find lot of thread on this one, how to validate a absence in ESS or via PA30
for example
http://scn.sap.com/thread/3360997https://wiki.scn.sap.com/wiki/display/ERPHCM/Validations+for+ESS+Leave+request
just search you ll find lot of thread on this one, how to validate a absence in ESS or via PA30
for example
http://scn.sap.com/thread/3360997https://wiki.scn.sap.com/wiki/display/ERPHCM/Validations+for+ESS+Leave+request