hi
i have a problem, with a vfp
recently i created a custom object Aspirante__c
then in the interface of this object add anew button that send me to one vfp
in this page a will update a loockup field
but i don't know how to pass the id od the record that i want to delete

the way that link the button with the page is with

window.location.href = "/apex/MyCustomLookup" when i created the button and then add on the format page

another problem is that i want to return to the prior page exactly of the record after that i click the button save
actually this redirect me but not update

this is my code

public with sharing class MyCustomLookupController1 {
    public String nombre {get;set;}
    public String vacante {get; set;}
    public String vacantebusqueda{get;set;}
   
     public Aspirante__c aspirante1 {get;set;}
    
     
    public Vacante__c oVacante{get;set;}
    
    public MyCustomLookupController1() {
    aspirante1= new Aspirante__c();
   

    }
    
    
    public void save() 
                {  
                    //consulta objeto aspirante al que voy actualizar  
                    Aspirante__c aspirante2 = [Select id, Name, Vacante__c from Aspirante__c where Id='a04d0000001phczAAA' Limit 1];//i want to take the id of the record
                 
                             
                  aspirante2.Vacante__c=aspirante1.Vacante__c; 
                 // aspirante2.Name=nombre;

                  update aspirante2; 
                 }  
    
}

<apex:page controller="MyCustomLookupController1" id="Page" tabstyle="Contact">
<apex:sectionHeader title="Aspirante"  subtitle="Asignar vacante" />

    <apex:form id="myForm">  
        <apex:PageBlock id="PageBlock">     
            <apex:pageBlockSection columns="1" title="Asignar vacante">
        <apex:inputField id="Vacante__c" value="{!aspirante1.Vacante__c}"  />
        
          
       <apex:commandButton action="{!save}" 
                value="Guardar"  onclick="history.go(-1);return false;"/>
            </apex:pageBlockSection>
        </apex:PageBlock>
    </apex:form>
       
</apex:page>