In addressing the issue posed by counsel, the Court has treated the Civil Support Petition filed herein as a Petition to Modify a Separation Agreement. To do otherwise would be to treat the agreement as a nullity or non-existent. This being the case, the proceeding, therefore, has some characteristics which would seem to distinguish it from the line of cases referred to in Lewkowitz v. Lewkowitz, Del.Fam., 513 A.2d 211 (1985) which deals with personal jurisdiction over a respondent for the purpose of establishment, enforcement, or modification of judicially-ordered child support. Here we are dealing with an effort to obtain an upward modification of the child support provisions of a Separation Agreement negotiated by the parties at a time when the mother and children were residents of Delaware and the father resided in another state.

Again, it is evident that the contacts of the child in the cited case are more significant than those in the case at bar. This Court is well aware of the line of cases which hold that the last marital domicile is sufficient connection for jurisdiction in support matters, See, Prybolsky v. Prybolsky, Del.Fam., 430 A.2d 804 (1981), King v. King, Del.Fam., 513 A.2d 773 (1985), Helen B.M. v. Samuel F.D., Del.Fam., 479 A.2d 852 (1984), and that continuing jurisdiction exists over subsequent enforcement or modification of decrees Lewkowitz v. Lewkowitz, Del.Fam., 513 A.2d 211 (1985). However, in support cases, such as those referred to above, jurisdiction for support really involves only jurisdiction over the parents rather than jurisdiction over the child, whereas the focus of custody/visitation cases is much broader and also involves the child and his or her environment, school, personal relationships and other factors which have a particular situs.