Sending null without using 0 in WSDL

[SemueliWu]

I have this WSDL content:\[code\]<s:element minOccurs="0" maxOccurs="1" name="SystemName" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="SystemPassword" type="s:string"/><s:element minOccurs="1" maxOccurs="1" name="MS_ZIHUY" type="s:int"/><s:element minOccurs="1" maxOccurs="1" name="KOD_CHEVRA" type="s:int"/><s:element minOccurs="0" maxOccurs="1" name="FAMILY_NAME" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="FIRST_NAME" type="s:string"/><s:element minOccurs="1" maxOccurs="1" name="KOD_MIN" nillable="true" type="s:int"/><s:element minOccurs="1" maxOccurs="1" name="BIRTH_DATE" nillable="true" type="s:dateTime"/><s:element minOccurs="0" maxOccurs="1" name="SMOKING" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="CURRENT_OCCUPATION" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="INTERNET_INDICATOR" type="s:string"/><s:element minOccurs="1" maxOccurs="1" name="MS_SOCHEN_MEVUTACH_VIP" type="s:int"/><s:element minOccurs="0" maxOccurs="1" name="SEMEL_YESHUV" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="SHEM_YESHUV" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="SEMEL_RECHOV" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="SHEM_RECHOV" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="MS_BAIT" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="MS_DIRA" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="MS_KNISA" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="OT_BAIT" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="MIKUD" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="TA_DOAR" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="MARITAL_STATUS" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="MS_KIDOMET_TELEFON" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="MS_TELEFON" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="MS_KIDOMET_NAYAD" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="MS_NAYAD" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="MS_KIDOMET_FAX" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="MS_FAX" type="s:string"/><s:element minOccurs="0" maxOccurs="1" name="EMAIL" type="s:string"/><s:element minOccurs="1" maxOccurs="1" name="KOD_DIVUR_SHIVUKI" nillable="true" type="s:int"/> <s:element minOccurs="1" maxOccurs="1" name="KOD_DIVUR_SHIVUKI_ELC" nillable="true" type="s:int"/>\[/code\]but when I want to send null in this fields , i need to send 0 like that :\[code\]<tem:FAMILY_NAME>0</tem:FAMILY_NAME><tem:FIRST_NAME>0</tem:FIRST_NAME>\[/code\]this doesn't help :\[code\]<tem:FAMILY_NAME/><tem:FIRST_NAME/>\[/code\]What should I do if I want to send null